Exhibit 99.1

2004 AMENDED AND RESTATED EQUITY INCENTIVE PLAN OF THRESHOLD PHARMACEUTICALS, INC.

(as amended on May 22, 2009)

1. Purpose of this Plan

The purpose of this 2004 Amended and Restated Equity Incentive Plan is to enhance the long-term stockholder value of Threshold Pharmaceuticals, Inc. by offering opportunities to eligible individuals to participate in the growth in value of the equity of Threshold Pharmaceuticals, Inc.

2. Definitions and Rules of Interpretation

2.1 Definitions.

This Plan uses the following defined terms:

(a) “ Administrator ” means the Board or the Committee, or any officer or employee of the Company to whom the Board or the Committee delegates authority to administer this Plan.

(b) “ Affiliate ” means a “parent” or “subsidiary” (as each is defined in Section 424 of the Code) of the Company and any other entity that the Board or Committee designates as an “Affiliate” for purposes of this Plan.

(c) “ Applicable Law ” means any and all laws of whatever jurisdiction, within or without the United States, and the rules of any stock exchange or quotation system on which Shares are listed or quoted, applicable to the taking or refraining from taking of any action under this Plan, including the administration of this Plan and the issuance or transfer of Awards or Award Shares.

(d) “ Award ” means a Stock Award, SAR, Cash Award, or Option granted in accordance with the terms of this Plan.

(e) “ Award Agreement ” means the document evidencing the grant of an Award.

(f) “ Award Shares ” means Shares covered by an outstanding Award or purchased under an Award.

(g) “ Awardee ” means: (i) a person to whom an Award has been granted, including a holder of a Substitute Award, (ii) a person to whom an Award has been transferred in accordance with all applicable requirements of Sections 6.5, 7(h), and 16.

(h) “ Board ” means the Board of Directors of the Company.

(i) “ Cash Award ” means the right to receive cash as described in Section 8.3.

(j) “ Cause ” means employment related dishonesty, fraud, misconduct or disclosure or misuse of confidential information, or other employment related conduct that is likely to cause significant injury to the Company, an Affiliate, or any of their respective employees, officers or directors (including, without limitation, commission of a felony or similar offense), in each case as determined by the Administrator. “Cause” shall not require that a civil judgment or criminal conviction have been entered against or guilty plea shall have been made by the Awardee regarding any of the matters referred to in the previous sentence. Accordingly, the Administrator shall be entitled to determine “Cause” based on the Administrator’s good faith belief. If the Awardee is criminally charged with a felony or similar offense that shall be a sufficient, but not a necessary, basis for such belief.

(k) “ Change in Control ” means any transaction or event that the Board specifies as a Change in Control under Section 10.4.

(l) “ Code ” means the Internal Revenue Code of 1986.

(m) “ Committee ” means a committee composed of Company Directors appointed in accordance with the Company’s charter documents and Section 4.

(n) “ Company ” means Threshold Pharmaceuticals, Inc., a Delaware corporation.

(o) “ Company Director ” means a member of the Board.

(p) “ Consultant ” means an individual who, or an employee of any entity that, provides bona fide services to the Company or an Affiliate not in connection with the offer or sale of securities in a capital-raising transaction, but who is not an Employee.

(q) “ Director ” means a member of the Board of Directors of the Company or an Affiliate.

(r) “ Divestiture ” means any transaction or event that the Board specifies as a Divestiture under Section 10.5.

(s) “ Domestic Relations Order ” means a “domestic relations order” as defined in, and otherwise meeting the requirements of, Section 414(p) of the Code, except that reference to a “plan” in that definition shall be to this Plan.

(t) “ Effective Date ” means the first date of the sale by the Company of shares of its capital stock in an initial public offering pursuant to a registration statement on Form S-1 filed with the SEC.

(u) “ Employee ” means a regular employee of the Company or an Affiliate, including an officer or Director, who is treated as an employee in the personnel records of the Company or an Affiliate, but not individuals who are classified by the Company or an Affiliate as: (i) leased from or otherwise employed by a third party, (ii) independent contractors, or (iii) intermittent or temporary workers. The Company’s or an Affiliate’s classification of an individual as an “Employee” (or as not an “Employee”) for purposes of this Plan shall not be

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altered retroactively even if that classification is changed retroactively for another purpose as a result of an audit, litigation or otherwise. An Awardee shall not cease to be an Employee due to transfers between locations of the Company, or between the Company and an Affiliate, or to any successor to the Company or an Affiliate that assumes the Awardee’s Options under Section 10. Neither service as a Director nor receipt of a director’s fee shall be sufficient to make a Director an “Employee.”

(v) “ Exchange Act ” means the Securities Exchange Act of 1934.

(w) “ Executive ” means, if the Company has any class of any equity security registered under Section 12 of the Exchange Act, an individual who is subject to Section 16 of the Exchange Act or who is a “covered employee” under Section 162(m) of the Code, in either case because of the individual’s relationship with the Company or an Affiliate. If the Company does not have any class of any equity security registered under Section 12 of the Exchange Act, “Executive” means any (i) Director, (ii) officer elected or appointed by the Board, or (iii) beneficial owner of more than 10% of any class of the Company’s equity securities.

(x) “ Expiration Date ” means, with respect to an Award, the date stated in the Award Agreement as the expiration date of the Award or, if no such date is stated in the Award Agreement, then the last day of the maximum exercise period for the Award, disregarding the effect of an Awardee’s Termination or any other event that would shorten that period.

(y) “ Fair Market Value ” means the value of Shares as determined under Section 17.2.

(z) “ Fundamental Transaction ” means any transaction or event described in Section 10.3.

(aa) “ Good Reason ” means (i) a material diminution in responsibility or compensation, or (ii) requiring Awardee to work in a location (other than normal business travel) which is more than 50 miles from Awardee’s principal place of business before the change.

(bb) “ Grant Date ” means the date the Administrator approves the grant of an Award. However, if the Administrator specifies that an Award’s Grant Date is a future date or the date on which a condition is satisfied, the Grant Date for such Award is that future date or the date that the condition is satisfied.

(cc) “ Incentive Stock Option ” means an Option intended to qualify as an incentive stock option under Section 422 of the Code and designated as an Incentive Stock Option in the Award Agreement for that Option.

(dd) “ Involuntary Termination ” means termination by the Company without Cause or termination by the Awardee for Good Reason.

(ee) “ Nonstatutory Option ” means any Option other than an Incentive Stock Option.

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(ff) “ Objectively Determinable Performance Condition ” shall mean a performance condition (i) that is established (A) at the time an Award is granted or (B) no later than the earlier of (1) 90 days after the beginning of the period of service to which it relates, or (2) before the elapse of 25% of the period of service to which it relates, (ii) that is uncertain of achievement at the time it is established, and (iii) the achievement of which is determinable by a third party with knowledge of the relevant facts. Examples of measures that may be used in Objectively Determinable Performance Conditions include net order dollars, net profit dollars, net profit growth, net revenue dollars, revenue growth, individual performance, earnings per share, return on assets, return on equity, and other financial objectives, objective customer satisfaction indicators and efficiency measures, each with respect to the Company and/or an Affiliate or individual business unit.

(gg) “ Officer ” means an officer of the Company as defined in Rule 16a-1 adopted under the Exchange Act.

(hh) “ Option ” means a right to purchase Shares of the Company granted under this Plan.

(ii) “ Option Price ” means the price payable under an Option for Shares, not including any amount payable in respect of withholding or other taxes.

(jj) “ Option Shares ” means Shares covered by an outstanding Option or purchased under an Option.

(kk) “ Plan ” means this 2004 Amended and Restated Equity Incentive Plan of Threshold Pharmaceuticals, Inc.

(ll) “ Prior Plan ” means the Company’s 2001 Equity Incentive Plan.

(mm) “ Purchase Price ” means the price payable under a Stock Award for Shares, not including any amount payable in respect of withholding or other taxes.

(nn) “ Rule 16b-3 ” means Rule 16b-3 adopted under Section 16(b) of the Exchange Act.

(oo) “ SAR ” or “ Stock Appreciation Right ” means a right to receive cash and/or Shares based on a change in the Fair Market Value of a specific number of Shares pursuant to an Award Agreement, as described in Section 8.1.

(pp) “ Securities Act ” means the Securities Act of 1933.

(qq) “ Share ” means a share of the common stock of the Company or other securities substituted for the common stock under Section 10.

(rr) “ Stock Award ” means an offer by the Company to sell shares subject to certain restrictions pursuant to the Award Agreement as described in Section 8.2 or, as determined by the Committee, a notional account representing the right to be paid an amount based on Shares.

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(ss) “ Substitute Award ” means a Substitute Option, Substitute SAR or Substitute Stock Award granted in accordance with the terms of this Plan.

(tt) “ Substitute Option ” means an Option granted in substitution for, or upon the conversion of, an option granted by another entity to purchase equity securities in the granting entity.

(uu) “ Substitute SAR ” means a SAR granted in substitution for, or upon the conversion of, a stock appreciation right granted by another entity with respect to equity securities in the granting entity.

(vv) “ Substitute Stock Award ” means a Stock Award granted in substitution for, or upon the conversion of, a stock award granted by another entity to purchase equity securities in the granting entity.

(ww) “ Termination ” means that the Awardee has ceased to be, with or without any cause or reason, an Employee, Director or Consultant. However, unless so determined by the Administrator, or otherwise provided in this Plan, “Termination” shall not include a change in status from an Employee, Consultant or Director to another such status. An event that causes an Affiliate to cease being an Affiliate shall be treated as the “Termination” of that Affiliate’s Employees, Directors, and Consultants.

2.2 Rules of Interpretation . Any reference to a “Section,” without more, is to a Section of this Plan. Captions and titles are used for convenience in this Plan and shall not, by themselves, determine the meaning of this Plan. Except when otherwise indicated by the context, the singular includes the plural and vice versa. Any reference to a statute is also a reference to the applicable rules and regulations adopted under that statute. Any reference to a statute, rule or regulation, or to a section of a statute, rule or regulation, is a reference to that statute, rule, regulation, or section as amended from time to time, both before and after the Effective Date and including any successor provisions.

3. Shares Subject to this Plan; Term of this Plan

3.1 Number of Award Shares . The Shares issuable under this Plan shall be authorized but unissued or reacquired Shares, including Shares repurchased by the Company on the open market. The number of Shares initially reserved for issuance over the term of this Plan shall be 404,801 ¹ . Except as required by Applicable Law, Shares shall not reduce the number of Shares reserved for issuance under this Plan until the earlier of the date such Shares are vested pursuant to the terms of the applicable Award or the actual date of delivery of the Shares to the Awardee. Notwithstanding the foregoing, the maximum number of Shares shall be increased by (i) the number of shares available for issuance, as of the Effective Date, under the Prior Plan as last approved by the Company’s stockholders, including the Shares subject to outstanding awards under the Prior Plan, plus (ii) those Shares issued under the Plan or Prior Plan that are forfeited or repurchased by the Company at the original purchase price or less or that are issuable upon exercise of awards granted under the Plan or Prior Plan that expire or become unexercisable for any reason after the Effective Date, plus (iii) those Shares that are Restored

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pursuant to the decision of the Board or Committee pursuant to Section 6.4(a) to deliver only such Shares as are necessary to award the net Share appreciation. The repurchase of Shares by the Company shall not increase the maximum number of Shares that may be issued under this Plan to the extent the Company repurchases Shares that were originally exercised or purchased with other previously owned Shares. The maximum number of Shares shall be cumulatively increased on the first January 1 after the Effective Date and each January 1 thereafter for 9 more years, by a number of Shares equal to the lesser of (a) 5% of the number of Shares issued and outstanding on the immediately preceding December 31, (b) 202,401 ²  Shares, and (c) a number of Shares set by the Board.

3.2 Source of Shares . Award Shares may be: (a) Shares that have never been issued, (b) Shares that have been issued but are no longer outstanding, or (c) Shares that are outstanding and are acquired to discharge the Company’s obligation to deliver Award Shares.

3.3 Term of this Plan

(a) This Plan shall be effective on, and Awards may be granted under this Plan on and after, the earliest the date on which the Plan has been both adopted by the Board and approved by the Company’s stockholders.

(b) Subject to the provisions of Section 13, Awards may be granted under this Plan for a period of ten years from the earlier of the date on which the Board approves this Plan and the date the Company’s stockholders approve this Plan. Accordingly, Awards may not be granted under this Plan after the earlier of those dates.

4. Administration

4.1 General

(a) The Board shall have ultimate responsibility for administering this Plan. The Board may delegate certain of its responsibilities to a Committee, which shall consist of at least two members of the Board. The Board or the Committee may further delegate its responsibilities to any Employee of the Company or any Affiliate. Where this Plan specifies that an action is to be taken or a determination made by the Board, only the Board may take that action or make that determination. Where this Plan specifies that an action is to be taken or a determination made by the Committee, only the Committee may take that action or make that determination. Where this Plan references the “Administrator,” the action may be taken or determination made by the Board, the Committee, or other Administrator. However, only the Board or the Committee may approve grants of Awards to Executives, and an Administrator other than the Board or the Committee may grant Awards only within the guidelines established by the Board or Committee. Moreover, all actions and determinations by any Administrator are subject to the provisions of this Plan.

(b) So long as the Company has registered a class of equity securities under Section 12 of the Exchange Act, the Committee shall consist of Company Directors who are “Non-Employee Directors” as defined in Rule 16b-3 and, after the expiration of any transition

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period permitted by Treasury Regulations Section 1.162-27(h)(3), who are “outside directors” as defined in Section 162(m) of the Code.

4.2 Authority of the Board or the Committee . Subject to the other provisions of this Plan, the Board or the Committee shall have the authority to:

(a) grant Awards, including Substitute Awards;

(b) determine the Fair Market Value of Shares;

(c) determine the Option Price and the Purchase Price of Awards;

(d) select the Awardees;

(e) determine the times Awards are granted;

(f) determine the number of Shares subject to each Award;

(g) determine the methods of payment that may be used to purchase Award Shares;

(h) determine the methods of payment that may be used to satisfy withholding tax obligations;

(i) determine the other terms of each Award, including but not limited to the time or times at which Awards may be exercised, whether and under what conditions an Award is assignable, and whether an Option is a Nonstatutory Option or an Incentive Stock Option;

(j) modify or amend any Award;

(k) authorize any person to sign any Award Agreement or other document related to this Plan on behalf of the Company;

(l) determine the form of any Award Agreement or other document related to this Plan, and whether that document, including signatures, may be in electronic form;

(m) interpret this Plan and any Award Agreement or document related to this Plan;

(n) correct any defect, remedy any omission, or reconcile any inconsistency in this Plan, any Award Agreement or any other document related to this Plan;

(o) adopt, amend, and revoke rules and regulations under this Plan, including rules and regulations relating to sub-plans and Plan addenda;

(p) adopt, amend, and revoke special rules and procedures which may be inconsistent with the terms of this Plan, set forth (if the Administrator so chooses) in sub-plans regarding (for example) the operation and administration of this Plan and the terms of Awards, if and to the extent necessary or useful to accommodate non-U.S. Applicable Laws and practices as

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they apply to Awards and Award Shares held by, or granted or issued to, persons working or resident outside of the United States or employed by Affiliates incorporated outside the United States;

(q) determine whether a transaction or event should be treated as a Change in Control, a Divestiture or neither;

(r) determine the effect of a Fundamental Transaction and, if the Board determines that a transaction or event should be treated as a Change in Control or a Divestiture, then the effect of that Change in Control or Divestiture; and

(s) make all other determinations the Administrator deems necessary or advisable for the administration of this Plan.

4.3 Scope of Discretion . Subject to the provisions of this Section 4.3, on all matters for which this Plan confers the authority, right or power on the Board, the Committee, or other Administrator to make decisions, that body may make those decisions in its sole and absolute discretion. Those decisions will be final, binding and conclusive. In making its decisions, the Board, Committee or other Administrator need not treat all persons eligible to receive Awards, all Awardees, all Awards or all Award Shares the same way. Notwithstanding anything herein to the contrary, and except as provided in Section 13.3, the discretion of the Board, Committee or other Administrator is subject to the specific provisions and specific limitations of this Plan, as well as all rights conferred on specific Awardees by Award Agreements and other agreements.

5. Persons Eligible to Receive Awards

5.1 Eligible Individuals . Awards (including Substitute Awards) may be granted to, and only to, Employees, Directors and Consultants, including to prospective Employees, Directors and Consultants conditioned on the beginning of their service for the Company or an Affiliate. However, Incentive Stock Options may only be granted to Employees, as provided in Section 7(g).

5.2 Section 162(m) Limitation.

(a) Options and SARs . Subject to the provisions of this Section 5.2, for so long as the Company is a “publicly held corporation” within the meaning of Section 162(m) of the Code: (i) no Employee may be granted one or more SARs and Options within any fiscal year of the Company under this Plan to purchase more than 202,401 ³ Shares under Options or to receive compensation calculated with reference to more than that number of Shares under SARs, subject to adjustment pursuant to Section 10, (ii) Options and SARs may be granted to an Executive only by the Committee (and, notwithstanding anything to the contrary in Section 4.1(a), not by the Board). If an Option or SAR is cancelled without being exercised or if the Option Price of an Option is reduced, that cancelled or repriced Option or SAR shall continue to be counted against the limit on Awards that my be granted to any individual under this Section 5.2. Notwithstanding anything herein to the contrary, a new Employee of the Company

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or an Affiliate shall be eligible to receive up to a maximum of 303,601 ⁴ Shares under Options in the calendar year which they commence employment, or such compensation calculated with reference to such number of Shares under SARs, subject to adjustment pursuant to Section 10.

(b) Cash Awards and Stock Awards . Any Cash Award or Stock Award intended as “qualified performance-based compensation” within the meaning of Section 162(m) of the Code must vest or become exercisable contingent on the achievement of one or more Objectively Determinable Performance Conditions. The Committee shall have the discretion to determine the time and manner of compliance with Section 162(m) of the Code.

6. Terms and Conditions of Options

The following rules apply to all Options:

6.1 Price . Except as specifically provided herein, no Nonstatutory Option may have an Option Price less than 85% of the Fair Market Value of the Shares on the Grant Date. No Option intended as “qualified incentive-based compensation” within the meaning of Section 162(m) of the Code may have an Option Price less than 100% of the Fair Market Value of the Shares on the Grant Date. In no event will the Option Price of any Option be less than the par value of the Shares issuable under the Option if that is required by Applicable Law. The Option Price of an Incentive Stock Option shall be subject to Section 7(f).

6.2 Term . No Option shall be exercisable after its Expiration Date. No Option may have an Expiration Date that is more than ten years after its Grant Date. Additional provisions regarding the term of Incentive Stock Options are provided in Sections 7(a) and 7(e).

6.3 Vesting . Options shall be exercisable: (a) on the Grant Date, or (b) in accordance with a schedule related to the Grant Date, the date the Optionee’s directorship, employment or consultancy begins, or a different date specified in the Option Agreement. Additional provisions regarding the vesting of Incentive Stock Options are provided in Section 7(c). No Option granted to an individual who is subject to the overtime pay provisions of the Fair Labor Standards Act may be exercised before the expiration of six months after the Grant Date.

6.4 Form and Method of Payment .

(a) The Board or Committee shall determine the acceptable form and method of payment for exercising an Option. So long as variable accounting pursuant to “APB 25” does not apply and the Board or Committee otherwise determines there is no material adverse accounting consequence at the time of exercise, the Board or Committee may require the delivery in Shares for the value of the net appreciation of the Shares at the time of exercise over the exercise price. The difference between full number of Shares covered by the exercised portion of the Award and the number of Shares actually delivered shall be restored to the amount of Shares reserved for issuance under Section 3.1.

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(b) Acceptable forms of payment for all Option Shares are cash, check or wire transfer, denominated in U.S. dollars except as specified by the Administrator for non-U.S. Employees or non-U.S. sub-plans.

(c) In addition, the Administrator may permit payment to be made by any of the following methods:

(i) other Shares, or the designation of other Shares, which (A) are “mature” shares for purposes of avoiding variable accounting treatment under generally accepted accounting principles (generally mature shares are those that have been owned by the Optionee for more than six months on the date of surrender), and (B) have a Fair Market Value on the date of surrender equal to the Option Price of the Shares as to which the Option is being exercised;

(ii) provided that a public market exists for the Shares, consideration received by the Company under a procedure under which a licensed broker-dealer advances funds on behalf of an Optionee or sells Option Shares on behalf of an Optionee (a “ Cashless Exercise Procedure ”), provided that if the Company extends or arranges for the extension of credit to an Optionee under any Cashless Exercise Procedure, no Officer or Director may participate in that Cashless Exercise Procedure;

(iii) cancellation of any debt owed by the Company or any Affiliate to the Optionee by the Company including without limitation waiver of compensation due or accrued for services previously rendered to the Company; and

(iv) any combination of the methods of payment permitted by any paragraph of this Section 6.4.

(d) The Administrator may also permit any other form or method of payment for Option Shares permitted by Applicable Law.

6.5 Nonassignability of Options . Except as determined by the Administrator, no Option shall be assignable or otherwise transferable by the Optionee except by will or by the laws of descent and distribution. However, Options may be transferred and exercised in accordance with a Domestic Relations Order and may be exercised by a guardian or conservator appointed to act for the Optionee. Incentive Stock Options may only be assigned in compliance with Section 7(h).

6.6 Substitute Options . The Board may cause the Company to grant Substitute Options in connection with the acquisition by the Company or an Affiliate of equity securities of any entity (including by merger, tender offer, or other similar transaction) or of all or a portion of the assets of any entity. Any such substitution shall be effective on the effective date of the acquisition. Substitute Options may be Nonstatutory Options or Incentive Stock Options. Unless and to the extent specified otherwise by the Board, Substitute Options shall have the same terms and conditions as the options they replace, except that (subject to the provisions of Section 10) Substitute Options shall be Options to purchase Shares rather than equity securities of the granting entity and shall have an Option Price determined by the Board.

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6.7 Repricings . Options may be repriced, replaced or regranted through cancellation or modification.

7. Incentive Stock Options.

The following rules apply only to Incentive Stock Options and only to the extent these rules are more restrictive than the rules that would otherwise apply under this Plan. With the consent of the Optionee, or where this Plan provides that an action may be taken notwithstanding any other provision of this Plan, the Administrator may deviate from the requirements of this Section, notwithstanding that any Incentive Stock Option modified by the Administrator will thereafter be treated as a Nonstatutory Option.

(a) The Expiration Date of an Incentive Stock Option shall not be later than ten years from its Grant Date, with the result that no Incentive Stock Option may be exercised after the expiration of ten years from its Grant Date.

(b) No Incentive Stock Option may be granted more than ten years from the date this Plan was approved by the Board.

(c) Options intended to be incentive stock options under Section 422 of the Code that are granted to any single Optionee under all incentive stock option plans of the Company and its Affiliates, including incentive stock options granted under this Plan, may not vest at a rate of more than $100,000 in Fair Market Value of stock (measured on the grant dates of the options) during any calendar year. For this purpose, an option vests with respect to a given share of stock the first time its holder may purchase that share, notwithstanding any right of the Company to repurchase that share. Unless the administrator of that option plan specifies otherwise in the related agreement governing the option, this vesting limitation shall be applied by, to the extent necessary to satisfy this $100,000 rule, treating certain stock options that were intended to be incentive stock options under Section 422 of the Code as Nonstatutory Options. The stock options or portions of stock options to be reclassified as Nonstatutory Options are those with the highest option prices, whether granted under this Plan or any other equity compensation plan of the Company or any Affiliate that permits that treatment. This Section 7(c) shall not cause an Incentive Stock Option to vest before its original vesting date or cause an Incentive Stock Option that has already vested to cease to be vested.

(d) In order for an Incentive Stock Option to be exercised for any form of payment other than those described in Section 6.4(b), that right must be stated at the time of grant in the Option Agreement relating to that Incentive Stock Option.

(e) Any Incentive Stock Option granted to a Ten Percent Stockholder, must have an Expiration Date that is not later than five years from its Grant Date, with the result that no such Option may be exercised after the expiration of five years from the Grant Date. A “ Ten Percent Stockholder ” is any person who, directly or by attribution under Section 424(d) of the Code, owns stock possessing more than ten percent of the total combined voting power of all classes of stock of the Company or of any Affiliate on the Grant Date.

(f) The Option Price of an Incentive Stock Option shall never be less than the Fair Market Value of the Shares at the Grant Date. The Option Price for the Shares covered by

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an Incentive Stock Option granted to a Ten Percent Stockholder shall never be less than 110% of the Fair Market Value of the Shares at the Grant Date.

(g) Incentive Stock Options may be granted only to Employees. If an Optionee changes status from an Employee to a Consultant, that Optionee’s Incentive Stock Options become Nonstatutory Options if not exercised within the time period described in Section 7(i) (determined by treating that change in status as a Termination solely for purposes of this Section 7(g)).

(h) No rights under an Incentive Stock Option may be transferred by the Optionee, other than by will or the laws of descent and distribution. During the life of the Optionee, an Incentive Stock Option may be exercised only by the Optionee. The Company’s compliance with a Domestic Relations Order, or the exercise of an Incentive Stock Option by a guardian or conservator appointed to act for the Optionee, shall not violate this Section 7(h).

(i) An Incentive Stock Option shall be treated as a Nonstatutory Option if it remains exercisable after, and is not exercised within, the three-month period beginning with the Optionee’s Termination for any reason other than the Optionee’s death or disability (as defined in Section 22(e) of the Code). In the case of Termination due to death, an Incentive Stock Option shall continue to be treated as an Incentive Stock Option if it remains exercisable after, and is not exercised within, the three month period after the Optionee’s Termination provided it is exercised before the Expiration Date. In the case of Termination due to disability, an Incentive Stock Option shall be treated as a Nonstatutory Option if it remains exercisable after, and is not exercised within, one year after the Optionee’s Termination.

(j) An Incentive Stock Option may only be modified by the Board.

8. Stock Appreciation Rights, Stock Awards and Cash Awards

8.1 Stock Appreciation Rights . The following rules apply to SARs:

(a) General . SARs may be granted either alone, in addition to, or in tandem with other Awards granted under this Plan. The Administrator may grant SARs to eligible participants subject to terms and conditions not inconsistent with this Plan and determined by the Administrator. The specific terms and conditions applicable to the Awardee shall be provided for in the Award Agreement. SARs shall be exercisable, in whole or in part, at such times as the Administrator shall specify in the Award Agreement. The grant or vesting of a SAR may be made contingent on the achievement of Objectively Determinable Performance Conditions.

(b) Exercise of SARs . Upon the exercise of an SAR, in whole or in part, an Awardee shall be entitled to a payment in an amount equal to the excess of the Fair Market Value of a fixed number of Shares covered by the exercised portion of the SAR on the date of exercise, over the Fair Market Value of the Shares covered by the exercised portion of the SAR on the Grant Date. The amount due to the Awardee upon the exercise of a SAR shall be paid in cash, Shares or a combination thereof, over the period or periods specified in the Award Agreement. An Award Agreement may place limits on the amount that may be paid over any specified period or periods upon the exercise of a SAR, on an aggregate basis or as to any Awardee. A SAR shall be considered exercised when the Company receives written notice of

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exercise in accordance with the terms of the Award Agreement from the person entitled to exercise the SAR. If a SAR has been granted in tandem with an Option, upon the exercise of the SAR, the number of shares that may be purchased pursuant to the Option shall be reduced by the number of shares with respect to which the SAR is exercised.

(c) Nonassignability of SARs . Except as determined by the Administrator, no SAR shall be assignable or otherwise transferable by the Awardee except by will or by the laws of descent and distribution. Notwithstanding anything herein to the contrary, SARs may be transferred and exercised in accordance with a Domestic Relations Order.

(d) Substitute SARs . The Board may cause the Company to grant Substitute SARs in connection with the acquisition by the Company or an Affiliate of equity securities of any entity (including by merger) or all or a portion of the assets of any entity. Any such substitution shall be effective on the effective date of the acquisition. Unless and to the extent specified otherwise by the Board, Substitute SARs shall have the same terms and conditions as the options they replace, except that (subject to the provisions of Section 9) Substitute SARs shall be exercisable with respect to the Fair Market Value of Shares rather than equity securities of the granting entity and shall be on terms that, as determined by the Board in its sole and absolute discretion, properly reflects the substitution.

(e) Repricings . A SAR may be repriced, replaced or regranted, through cancellation or modification.

8.2 Stock Awards . The following rules apply to all Stock Awards:

(a) General . The specific terms and conditions of a Stock Award applicable to the Awardee shall be provided for in the Award Agreement. The Award Agreement shall state the number of Shares that the Awardee shall be entitled to receive or purchase, the terms and conditions on which the Shares shall vest, the price to be paid, whether Shares are to be delivered at the time of grant or at some deferred date specified in the Award Agreement, whether the Award is payable solely in Shares, cash or either and, if applicable, the time within which the Awardee must accept such offer. The offer shall be accepted by execution of the Award Agreement. The Administrator may require that all Shares subject to a right of repurchase or risk of forfeiture be held in escrow until such repurchase right or risk of forfeiture lapses. The grant or vesting of a Stock Award may be made contingent on the achievement of Objectively Determinable Performance Conditions.

(b) Right of Repurchase . If so provided in the Award Agreement, Award Shares acquired pursuant to a Stock Award may be subject to repurchase by the Company or an Affiliate if not vested in accordance with the Award Agreement.

(c) Form of Payment . The Administrator shall determine the acceptable form and method of payment for exercising a Stock Award. Acceptable forms of payment for all Award Shares are cash, check or wire transfer, denominated in U.S. dollars except as specified by the Administrator for non-U.S. sub-plans. In addition, the Administrator may permit payment to be made by any of the methods permitted with respect to the exercise of Options pursuant to Section 6.4.

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(d) Nonassignability of Stock Awards . Except as determined by the Administrator, no Stock Award shall be assignable or otherwise transferable by the Awardee except by will or by the laws of descent and distribution. Notwithstanding anything to the contrary herein, Stock Awards may be transferred and exercised in accordance with a Domestic Relations Order.

(e) Substitute Stock Award . The Board may cause the Company to grant Substitute Stock Awards in connection with the acquisition by the Company or an Affiliate of equity securities of any entity (including by merger) or all or a portion of the assets of any entity. Unless and to the extent specified otherwise by the Board, Substitute Stock Awards shall have the same terms and conditions as the stock awards they replace, except that (subject to the provisions of Section 10) Substitute Stock Awards shall be Stock Awards to purchase Shares rather than equity securities of the granting entity and shall have a Purchase Price that, as determined by the Board in its sole and absolute discretion, properly reflects the substitution. Any such Substituted Stock Award shall be effective on the effective date of the acquisition.

8.3 Cash Awards . The following rules apply to all Cash Awards:

Cash Awards may be granted either alone, in addition to, or in tandem with other Awards granted under this Plan. After the Administrator determines that it will offer a Cash Award, it shall advise the Awardee, by means of an Award Agreement, of the terms, conditions and restrictions related to the Cash Award.

9. Exercise of Awards

9.1 In General . An Award shall be exercisable in accordance with this Plan and the Award Agreement under which it is granted.

9.2 Time of Exercise . Options and Stock Awards shall be considered exercised when the Company receives: (a) written notice of exercise from the person entitled to exercise the Option or Stock Award, (b) full payment, or provision for payment, in a form and method approved by the Administrator, for the Shares for which the Option or Stock Award is being exercised, and (c) with respect to Nonstatutory Options, payment, or provision for payment, in a form approved by the Administrator, of all applicable withholding taxes due upon exercise. An Award may not be exercised for a fraction of a Share. SARs shall be considered exercised when the Company receives written notice of the exercise from the person entitled to exercise the SAR.

9.3 Issuance of Award Shares . The Company shall issue Award Shares in the name of the person properly exercising the Award. If the Awardee is that person and so requests, the Award Shares shall be issued in the name of the Awardee and the Awardee’s spouse. The Company shall endeavor to issue Award Shares promptly after an Award is exercised or after the Grant Date of a Stock Award, as applicable. Until Award Shares are actually issued, as evidenced by the appropriate entry on the stock register of the Company or its transfer agent, the Awardee will not have the rights of a stockholder with respect to those Award Shares, even though the Awardee has completed all the steps necessary to exercise the Award. No adjustment

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shall be made for any dividend, distribution, or other right for which the record date precedes the date the Award Shares are issued, except as provided in Section 10.

9.4 Termination

(a) In General . Except as provided in an Award Agreement or in writing by the Administrator, including in an Award Agreement, and as otherwise provided in Sections 9.4(b), (c), (d) and (e) after an Awardee’s Termination for other than Cause, the Awardee’s Awards shall be exercisable to the extent (but only to the extent) they are vested on the date of that Termination and only during the ninety (90) days after the Termination, but in no event after the Expiration Date. Unless otherwise provided in the Award Agreement, in the event of termination for Cause the Award may not be exercised after the date of Termination. To the extent the Awardee does not exercise an Award within the time specified for exercise, the Award shall automatically terminate.

(b) Leaves of Absence . Unless otherwise provided in the Award Agreement, no Award may be exercised more than three months after the beginning of a leave of absence, other than a personal or medical leave approved by an authorized representative of the Company with employment guaranteed upon return. Awards shall not continue to vest during a leave of absence, unless otherwise determined by the Administrator with respect to an approved personal or medical leave with employment guaranteed upon return.

(c) Death or Disability . Unless otherwise provided by the Administrator, if an Awardee’s Termination is due to death or disability (as determined by the Administrator with respect to all Awards other than Incentive Stock Options and as defined by Section 22(e) of the Code with respect to Incentive Stock Options), all Awards of that Awardee to the extent exercisable at the date of that Termination may be exercised for one year after that Termination, but in no event after the Expiration Date. In the case of Termination due to death, an Award may be exercised as provided in Section 16. In the case of Termination due to disability, if a guardian or conservator has been appointed to act for the Awardee and been granted this authority as part of that appointment, that guardian or conservator may exercise the Award on behalf of the Awardee. Death or disability occurring after an Awardee’s Termination shall not cause the Termination to be treated as having occurred due to death or disability. To the extent an Award is not so exercised within the time specified for its exercise, the Award shall automatically terminate.

(d) Divestiture . If an Awardee’s Termination is due to a Divestiture, the Board may take any one or more of the actions described in Section 10.3 or 10.4 with respect to the Awardee’s Awards.

(e) Administrator Discretion . Notwithstanding the provisions of Section 9.4(a)–(e), the Plan Administrator shall have complete discretion, exercisable either at the time an Award is granted or at any time while the Award remains outstanding, to:

(i) Extend the period of time for which the Award is to remain exercisable, following the Awardee’s Termination, from the limited exercise period otherwise in

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effect for that Award to such greater period of time as the Administrator shall deem appropriate, but in no event beyond the Expiration Date; and/or

(ii) Permit the Award to be exercised, during the applicable post-Termination exercise period, not only with respect to the number of vested Shares for which such Award may be exercisable at the time of the Awardee’s Termination but also with respect to one or more additional installments in which the Awardee would have vested had the Awardee not been subject to Termination.

(f) Consulting or Employment Relationship . Nothing in this Plan or in any Award Agreement, and no Award or the fact that Award Shares remain subject to repurchase rights, shall: (A) interfere with or limit the right of the Company or any Affiliate to terminate the employment or consultancy of any Awardee at any time, whether with or without cause or reason, and with or without the payment of severance or any other compensation or payment, or (B) interfere with the application of any provision in any of the Company’s or any Affiliate’s charter documents or Applicable Law relating to the election, appointment, term of office, or removal of a Director.

10. Certain Transactions and Events

10.1 In General . Except as provided in this Section 10, no change in the capital structure of the Company, merger, sale or other disposition of assets or a subsidiary, change in control, issuance by the Company of shares of any class of securities or securities convertible into shares of any class of securities, exchange or conversion of securities, or other transaction or event shall require or be the occasion for any adjustments of the type described in this Section 10. Additional provisions with respect to the foregoing transactions are set forth in Section 13.3.

10.2 Changes in Capital Structure . In the event of any stock split, reverse stock split, recapitalization, combination or reclassification of stock, stock dividend, spin-off, or similar change to the capital structure of the Company (not including a Fundamental Transaction or Change in Control), the Board shall make whatever adjustments it concludes are appropriate to: (a) the number and type of Awards that may be granted under this Plan, (b) the number and type of Options that may be granted to any individual under this Plan, (c) the terms of any SAR, (d) the Purchase Price of any Stock Award, (e) the Option Price and number and class of securities issuable under each outstanding Option, and (f) the repurchase price of any securities substituted for Award Shares that are subject to repurchase rights. The specific adjustments shall be determined by the Board. Unless the Board specifies otherwise, any securities issuable as a result of any such adjustment shall be rounded down to the next lower whole security. The Board need not adopt the same rules for each Award or each Awardee.

10.3 Fundamental Transactions . In the event of (a) a merger or consolidation in which the Company is not the surviving corporation (other than a merger or consolidation with a wholly-owned subsidiary, a reincorporation of the Company in a different jurisdiction, or other transaction in which there is no substantial change in the stockholders of the Company or their relative stock holdings and the Awards granted under this Plan are assumed, converted or replaced by the successor corporation, which assumption shall be binding on all Participants),

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(b) a merger in which the Company is the surviving corporation but after which the stockholders of the Company immediately prior to such merger (other than any stockholder that merges, or which owns or controls another corporation that merges, with the Company in such merger) cease to own their shares or other equity interest in the Company, (c) the sale of all or substantially all of the assets of the Company, or (d) the acquisition, sale, or transfer of more than 50% of the outstanding shares of the Company by tender offer or similar transaction (each, a “ Fundamental Transaction ”), any or all outstanding Awards may be assumed, converted or replaced by the successor corporation (if any), which assumption, conversion or replacement shall be binding on all participants under this Plan. In the alternative, the successor corporation may substitute equivalent Awards or provide substantially similar consideration to participants as was provided to stockholders (after taking into account the existing provisions of the Awards). The successor corporation may also issue, in place of outstanding Shares held by the participants, substantially similar shares or other property subject to repurchase restrictions no less favorable to the participant. In the event such successor corporation (if any) does not assume or substitute Awards, as provided above, pursuant to a transaction described in this Subsection 10.3, the vesting with respect to such Awards shall fully and immediately accelerate or the repurchase rights of the Company shall fully and immediately terminate, as the case may be, so that the Awards may be exercised or the repurchase rights shall terminate before, or otherwise in connection with the closing or completion of the Fundamental Transaction or event, but then terminate. Notwithstanding anything in this Plan to the contrary, the Committee may, in its sole discretion, provide that the vesting of any or all Award Shares subject to vesting or right of repurchase shall accelerate or lapse, as the case may be, upon a transaction described in this Section 10.3. If the Committee exercises such discretion with respect to Options, such Options shall become exercisable in full prior to the consummation of such event at such time and on such conditions as the Committee determines, and if such Options are not exercised prior to the consummation of the Fundamental Transaction, they shall terminate at such time as determined by the Committee. Subject to any greater rights granted to participants under the foregoing provisions of this Section 10.3, in the event of the occurrence of any Fundamental Transaction, any outstanding Awards shall be treated as provided in the applicable agreement or plan of merger, consolidation, dissolution, liquidation, or sale of assets.

10.4 Changes of Control . The Board may also, but need not, specify that other transactions or events constitute a “Change in Control.” The Board may do that either before or after the transaction or event occurs. Examples of transactions or events that the Board may treat as Changes of Control are: (a) any person or entity, including a “group” as contemplated by Section 13(d)(3) of the Exchange Act, acquires securities holding 30% or more of the total combined voting power or value of the Company, or (b) as a result of or in connection with a contested election of Company Directors, the persons who were Company Directors immediately before the election cease to constitute a majority of the Board. In connection with a Change in Control, notwithstanding any other provision of this Plan, the Board may, but need not, take any one or more of the actions described in Section 10.3. In addition, the Board may extend the date for the exercise of Awards (but not beyond their original Expiration Date). The Board need not adopt the same rules for each Award or each Awardee. Notwithstanding anything in this Plan to the contrary, in the event of an Involuntary Termination of services for any reason other than death, disability or Cause, within 18 months following the consummation of a Fundamental Transaction or Change in Control, any Awards, assumed or substituted in a Fundamental Transaction or Change in Control, which are subject to vesting conditions and/or the right of

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repurchase in favor of the Company or a successor entity, shall accelerate for 12 months of vesting so that such Award Shares are immediately exercisable upon Termination or, if subject to the right of repurchase in favor of the Company, such repurchase rights shall lapse as of the date of Termination. Such Awards shall be exercisable for a period of three (3) months following termination.

10.5 Divestiture . If the Company or an Affiliate sells or otherwise transfers equity securities of an Affiliate to a person or entity other than the Company or an Affiliate, or leases, exchanges or transfers all or any portion of its assets to such a person or entity, then the Board may specify that such transaction or event constitutes a “Divestiture.” In connection with a Divestiture, notwithstanding any other provision of this Plan, the Board may, but need not, take one or more of the actions described in Section 10.3 or 10.4 with respect to Awards of Award Shares held by, for example, Employees, Directors or Consultants for whom that transaction or event results in a Termination. The Board need not adopt the same rules for each Award or Awardee.

10.6 Dissolution . If the Company adopts a plan of dissolution, the Board may cause Awards to be fully vested and exercisable (but not after their Expiration Date) before the dissolution is completed but contingent on its completion and may cause the Company’s repurchase rights on Award Shares to lapse upon completion of the dissolution. The Board need not adopt the same rules for each Award or each Awardee. Notwithstanding anything herein to the contrary, in the event of a dissolution of the Company, to the extent not exercised before the earlier of the completion of the dissolution or their Expiration Date, Awards shall terminate immediately prior to the dissolution.

10.7 Cut-Back to Preserve Benefits . If the Administrator determines that the net after-tax amount to be realized by any Awardee, taking into account any accelerated vesting, termination of repurchase rights, or cash payments to that Awardee in connection with any transaction or event set forth in this Section 10 would be greater if one or more of those steps were not taken or payments were not made with respect to that Awardee’s Awards or Award Shares, then, at the election of the Awardee, to such extent, one or more of those steps shall not be taken and payments shall not be made.

11. Automatic Option Grants to Non-Employee Directors and Non-Employee Director Fee Option Grants

11.1 Automatic Option Grants to Non-Employee Directors.

(a) Grant Dates . Option grants to Non-Employee Directors shall be made on the dates specified below:

(i) Each Non-Employee Director who is first elected or appointed to the Board at any time after the effective date of this Plan shall automatically be granted, on the date of such initial election or appointment, an Option to purchase 5,000 ⁵  Shares (the “ Initial Grant ”).

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(ii) Commencing in 2005, on the date of each annual stockholders meeting, each individual who is to continue to serve as a Non-Employee Director shall automatically be granted an Option to purchase 10,000 ⁶ Shares (the “ Annual Grant ”), provided, however, that such individual has served as a Non-Employee Director for at least six (6) months.

(b) Exercise Price .

(i) The Option Price shall be equal to one hundred percent (100%) of the Fair Market Value of the Shares on the Option grant date.

(ii) The Option Price shall be payable in one or more of the alternative forms authorized pursuant to Section 6.4. Except to the extent the sale and remittance procedure specified thereunder is utilized, payment of the Option Price must be made on the date of exercise.

(c) Option Term . Each Option shall have a term of ten (10) years measured from the Option grant date.

(d) Exercise and Vesting of Options . Except as otherwise determined by the whole Board, the Shares underlying each Option granted pursuant to Section 11.1 shall vest and be exercisable as set forth below.

(i) Initial Grant . The Shares underlying each Option issued pursuant to the Initial Grant shall vest and be exercisable as to 2.7777% of the Shares on each monthly anniversary of the date of grant, rounded down to the nearest whole Share, for so long as the Non-Employee Director continuously remains a Director of, or a Consultant to, the Company.

(ii) Annual Grant . The Shares underlying each Option issued pursuant to the Annual Grant shall vest and be exercisable as to 8.3333% of the Shares on each monthly anniversary of the date of grant for the first 11 months following the date of grant and as to the remaining Shares on the date of the annual stockholders meeting for the year following the year of grant for such Option, rounded down to the nearest whole Share, for so long as the Non-Employee Director continuously remains a Director of, or a Consultant to, the Company.

(e) Termination of Service . The following provisions shall govern the exercise of any Options held by the Awardee at the time the Awardee ceases to serve as a Non-Employee Director, Employee or Consultant:

(i) In General . Except as otherwise provided in Section 10.3, after cessation of service (the “ Cessation Date ”), the Awardee’s Options shall be exercisable to the extent (but only to the extent) they are vested on the Cessation Date and only during the three months after such Cessation Date, but in no event after the Expiration Date. To the extent the Awardee does not exercise an Option within the time specified for exercise, the Option shall automatically terminate.

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(ii) Death or Disability . If an Awardee’s cessation of service is due to death or disability (as determined by the Board), all Options of that Awardee, to the extent exercisable upon such Cessation Date, may be exercised for one year after the Cessation Date, but in no event after the Expiration Date. In the case of a cessation of service due to death, an Option may be exercised as provided in Section 16. In the case of a cessation of service due to disability, if a guardian or conservator has been appointed to act for the Awardee and been granted this authority as part of that appointment, that guardian or conservator may exercise the Option on behalf of the Awardee. Death or disability occurring after an Awardee’s cessation of service shall not cause the cessation of service to be treated as having occurred due to death or disability. To the extent an Option is not so exercised within the time specified for its exercise, the Option shall automatically terminate.

(f) Board Discretion . The Awards under this Section 11.1 are not intended as the exclusive Awards that may be made to Non-Employee Directors under this Plan. The Board may, in its discretion, amend the Plan with respect to the terms of the Awards herein, may add or substitute other types of Awards or may temporarily or permanently suspend Awards hereunder, all without approval of the Company’s stockholders.

11.2 Director Fee Option Grants

(a) Option Grants . The Board shall have the sole and exclusive authority to determine the calendar year or years for which the Director fee option grant program (the “ Director Fee Option Program ”) is to be in effect. For each such calendar year the program is in effect, each Non-Employee Director may elect to apply all or any portion of the annual retainer fee otherwise payable in cash, for his or her service on the Board for that year, to the acquisition of a special Option grant under this Director Fee Option Program. Such election must be filed with the Company’s Chief Financial Officer prior to first day of the calendar year for which the annual retainer fee which is the subject of that election is otherwise payable. Each Non-Employee Director who files such a timely election shall automatically be granted an Option under this Director Fee Option Program on the first trading day in January in the calendar year for which the annual retainer fee which is the subject of that election would otherwise be payable in cash.

(b) Option Terms . Each Option shall be a Nonstatutory Option governed by the terms and conditions specified below.

(i) Exercise Price .

A. The Purchase Price shall be thirty-three and one-third percent (33  ¹ / 3 %) of the Fair Market Value per Share on the Option grant date.

B. The Purchase Price shall become immediately due upon exercise of the Option and shall be payable in one or more of the alternative forms authorized pursuant to Section 6.4 of this Plan. Except to the extent the sale and remittance procedure specified thereunder is utilized, payment of the Purchase Price must be made on the date that the Option is exercised.

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(ii) Number of Option Shares . The number of Shares subject to the Option shall be determined pursuant to the following formula (rounded down to the nearest whole number):

X = A ÷ (B x 66  ² / 3 %), where

X is the number of Option Shares,

A is the portion of the annual retainer fee subject to the Non-Employee Director’s election, and

B is the Fair Market Value of a Share on the option grant date.

(iii) Exercise and Term of Options . The Option shall become exercisable in a series of twelve (12) equal monthly installments upon the Awardee’s completion of each month of Board service over the twelve (12)-month period measured from the grant date. Each Option shall have a maximum term of ten (10) years measured from the Option grant date.

(iv) Termination of Board Service . Should the Awardee cease Board service for any reason (other than death or permanent disability) while holding one or more Options under this Director Fee Option Program, then each such Option shall remain exercisable, for any or all of the Shares for which the Option is exercisable at the time of such cessation of Board service, until the earlier of (x) the expiration of the ten (10)-year Option term or (y) the expiration of the three (3)-year period measured from the date of such cessation of Board service. However, each Option held by the Awardee under this Director Fee Option Program at the time of his or her cessation of Board service shall immediately terminate and cease to remain outstanding with respect to any and all Shares for which the Option is not otherwise at that time exercisable.

(v) Death or Permanent Disability . Should the Awardee’s service as a Board member cease by reason of death or permanent disability, then each Option held by such Awardee under this Director Fee Option Program shall immediately become exercisable for all the Shares at the time subject to that Option, and the Option may be exercised for any or all of those Shares as fully-vested Shares until the earlier of (x) the expiration of the ten (10)-year option term or (y) the expiration of the three (3)-year period measured from the date of such cessation of Board service.

Should the Awardee die after cessation of his or her Board service but while holding one or more Options under this Director Fee Option Program, then each such Option may be exercised, for any or all of the shares for which the Option is exercisable at the time of the Awardee’s cessation of Board service (less any Shares subsequently purchased by the Awardee prior to death), by the personal representative of the Awardee’s estate or by the person or persons to whom the Option is transferred pursuant to the Awardee’s will or in accordance with the laws of descent and distribution or by the designated beneficiary or beneficiaries of such option. Such right of exercise shall lapse, and the Option shall terminate, upon the earlier of (xx) the expiration of the ten (10)-year Option term or (yy) the three (3)-year period measured from the date of the Awardee’s cessation of Board service.

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11.3 Certain Transactions and Events

(a) In the event of a Fundamental Transaction while the Awardee remains a Non-Employee Director, the Shares at the time subject to each outstanding Option held by such Awardee pursuant to Section 11, but not otherwise vested, shall automatically vest in full so that each such Option shall, immediately prior to the effective date of the Fundamental Transaction, become exercisable for all the Shares as fully vested Shares and may be exercised for any or all of those vested Shares. Immediately following the consummation of the Fundamental Transaction, each Option shall terminate and cease to be outstanding, except to the extent assumed by the successor corporation (or Affiliate thereof).

(b) In the event of a Change in Control while the Awardee remains a Non-Employee Director, the Shares at the time subject to each outstanding Option held by such Awardee pursuant to Section 11, but not otherwise vested, shall automatically vest in full so that each such Option shall, immediately prior to the effective date of the Change in Control, become exercisable for all the Shares as fully vested Shares and may be exercised for any or all of those vested Shares. Each such Option shall remain exercisable for such fully vested Shares until the expiration or sooner termination of the Option term in connection with a Change in Control.

(c) Each Option which is assumed in connection with a Fundamental Transaction shall be appropriately adjusted, immediately after such Fundamental Transaction, to apply to the number and class of securities which would have been issuable to the Awardee in consummation of such Fundamental Transaction had the Option been exercised immediately prior to such Fundamental Transaction. Appropriate adjustments shall also be made to the Option Price payable per share under each outstanding Option, provided the aggregate Option Price payable for such securities shall remain the same. To the extent the actual holders of the Company’s outstanding Common Stock receive cash consideration for their Common Stock in consummation of the Fundamental Transaction, the successor corporation may, in connection with the assumption of the outstanding Options granted pursuant to Section 11, substitute one or more shares of its own common stock with a fair market value equivalent to the cash consideration paid per share of Common Stock in such Fundamental Transaction.

(d) The grant of Options pursuant to Section 11 shall in no way affect the right of the Company to adjust, reclassify, reorganize or otherwise change its capital or business structure or to merge, consolidate, dissolve, liquidate or sell or transfer all or any part of its business or assets.

(e) The remaining terms of each Option granted pursuant to Section 11 shall, as applicable, be the same as terms in effect for Awards granted under this Plan. Notwithstanding the foregoing, the provisions of Section 9.4 and Section 10 shall not apply to Options granted pursuant to Section 11.

11.4 Limited Transferability of Options . Each Option granted pursuant to Section 11 may be assigned in whole or in part during the Awardee’s lifetime to one or more members of the Awardee’s family or to a trust established exclusively for one or more such family members or to an entity in which the Awardee is majority owner or to the Awardee’s former spouse, to the extent such assignment is in connection with the Awardee’s estate or

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financial plan or pursuant to a Domestic Relations Order. The assigned portion may only be exercised by the person or persons who acquire a proprietary interest in the Option pursuant to the assignment. The terms applicable to the assigned portion shall be the same as those in effect for the Option immediately prior to such assignment and shall be set forth in such documents issued to the assignee as the Administrator may deem appropriate. The Awardee may also designate one or more persons as the beneficiary or beneficiaries of his or her outstanding Options under Section 11, and those Options shall, in accordance with such designation, automatically be transferred to such beneficiary or beneficiaries upon the Awardee’s death while holding those Options. Such beneficiary or beneficiaries shall take the transferred Options subject to all the terms and conditions of the applicable Award Agreement evidencing each such transferred Option, including (without limitation) the limited time period during which the Option may be exercised following the Awardee’s death.

12. Withholding and Tax Reporting

12.1 Tax Withholding Alternatives

(a) General . Whenever Award Shares are issued or become free of restrictions, the Company may require the Awardee to remit to the Company an amount sufficient to satisfy any applicable tax withholding requirement, whether the related tax is imposed on the Awardee or the Company. The Company shall have no obligation to deliver Award Shares or release Award Shares from an escrow or permit a transfer of Award Shares until the Awardee has satisfied those tax withholding obligations. Whenever payment in satisfaction of Awards is made in cash, the payment will be reduced by an amount sufficient to satisfy all tax withholding requirements.

(b) Method of Payment . The Awardee shall pay any required withholding using the forms of consideration described in Section 6.4(b), except that, in the discretion of the Administrator, the Company may also permit the Awardee to use any of the forms of payment described in Section 6.4(c). The Administrator, in its sole discretion, may also permit Award Shares to be withheld to pay required withholding. If the Administrator permits Award Shares to be withheld, the Fair Market Value of the Award Shares withheld, as determined as of the date of withholding, shall not exceed the amount determined by the applicable minimum statutory withholding rates.

12.2 Reporting of Dispositions . Any holder of Option Shares acquired under an Incentive Stock Option shall promptly notify the Administrator, following such procedures as the Administrator may require, of the sale or other disposition of any of those Option Shares if the disposition occurs during: (a) the longer of two years after the Grant Date of the Incentive Stock Option and one year after the date the Incentive Stock Option was exercised, or (b) such other period as the Administrator has established.

13. Compliance with Law

The grant of Awards and the issuance and subsequent transfer of Award Shares shall be subject to compliance with all Applicable Law, including all applicable securities laws. Awards may not be exercised, and Award Shares may not be transferred, in violation of Applicable Law.

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Thus, for example, Awards may not be exercised unless: (a) a registration statement under the Securities Act is then in effect with respect to the related Award Shares, or (b) in the opinion of legal counsel to the Company, those Award Shares may be issued in accordance with an applicable exemption from the registration requirements of the Securities Act and any other applicable securities laws. The failure or inability of the Company to obtain from any regulatory body the authority considered by the Company’s legal counsel to be necessary or useful for the lawful issuance of any Award Shares or their subsequent transfer shall relieve the Company of any liability for failing to issue those Award Shares or permitting their transfer. As a condition to the exercise of any Award or the transfer of any Award Shares, the Company may require the Awardee to satisfy any requirements or qualifications that may be necessary or appropriate to comply with or evidence compliance with any Applicable Law.

14. Amendment or Termination of this Plan or Outstanding Awards

14.1 Amendment and Termination . The Board may at any time amend, suspend, or terminate this Plan.

14.2 Stockholder Approval . The Company shall obtain the approval of the Company’s stockholders for any amendment to this Plan if stockholder approval is necessary or desirable to comply with any Applicable Law or with the requirements applicable to the grant of Awards intended to be Incentive Stock Options. The Board may also, but need not, require that the Company’s stockholders approve any other amendments to this Plan.

14.3 Effect . No amendment, suspension, or termination of this Plan, and no modification of any Award even in the absence of an amendment, suspension, or termination of this Plan, shall impair any existing contractual rights of any Awardee unless the affected Awardee consents to the amendment, suspension, termination, or modification. Notwithstanding anything herein to the contrary, no such consent shall be required if the Board determines, in its sole and absolute discretion, that the amendment, suspension, termination, or modification: (a) is required or advisable in order for the Company, this Plan or the Award to satisfy Applicable Law, to meet the requirements of any accounting standard or to avoid any adverse accounting treatment, or (b) in connection with any transaction or event described in Section 10, is in the best interests of the Company or its stockholders. The Board may, but need not, take the tax or accounting consequences to affected Awardees into consideration in acting under the preceding sentence. Those decisions shall be final, binding and conclusive. Termination of this Plan shall not affect the Administrator’s ability to exercise the powers granted to it under this Plan with respect to Awards granted before the termination of Award Shares issued under such Awards even if those Award Shares are issued after the termination.

15. Reserved Rights

15.1 Nonexclusivity of this Plan . This Plan shall not limit the power of the Company or any Affiliate to adopt other incentive arrangements including, for example, the grant or issuance of stock options, stock, or other equity-based rights under other plans.

15.2 Unfunded Plan . This Plan shall be unfunded. Although bookkeeping accounts may be established with respect to Awardees, any such accounts will be used merely as a

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convenience. The Company shall not be required to segregate any assets on account of this Plan, the grant of Awards, or the issuance of Award Shares. The Company and the Administrator shall not be deemed to be a trustee of stock or cash to be awarded under this Plan. Any obligations of the Company to any Awardee shall be based solely upon contracts entered into under this Plan, such as Award Agreements. No such obligations shall be deemed to be secured by any pledge or other encumbrance on any assets of the Company. Neither the Company nor the Administrator shall be required to give any security or bond for the performance of any such obligations.

16. Special Arrangements Regarding Award Shares

16.1 Escrow of Stock Certificates . To enforce any restrictions on Award Shares, the Administrator may require their holder to deposit the certificates representing Award Shares, with stock powers or other transfer instruments approved by the Administrator endorsed in blank, with the Company or an agent of the Company to hold in escrow until the restrictions have lapsed or terminated. The Administrator may also cause a legend or legends referencing the restrictions to be placed on the certificates.

16.2 Repurchase Rights

(a) General . If a Stock Award is subject to vesting conditions, the Company shall have the right, during the seven months after the Awardee’s Termination, to repurchase any or all of the Award Shares that were unvested as of the date of that Termination. The repurchase price shall be determined by the Administrator in accordance with this Section 16.2 which shall be either (i) the Purchase Price for the Award Shares (minus the amount of any cash dividends paid or payable with respect to the Award Shares for which the record date precedes the repurchase) or (ii) the lower of (A) the Purchase Price for the Shares or (B) the Fair Market Value of those Award Shares as of the date of the Termination. The repurchase price shall be paid in cash. The Company may assign this right of repurchase.

(b) Procedure . The Company or its assignee may choose to give the Awardee a written notice of exercise of its repurchase rights under this Section 16.2. However, the Company’s failure to give such a notice shall not affect its rights to repurchase Award Shares. The Company must, however, tender the repurchase price during the period specified in this Section 16.2 for exercising its repurchase rights in order to exercise such rights.

17. Beneficiaries

An Awardee may file a written designation of one or more beneficiaries who are to receive the Awardee’s rights under the Awardee’s Awards after the Awardee’s death. An Awardee may change such a designation at any time by written notice. If an Awardee designates a beneficiary, the beneficiary may exercise the Awardee’s Awards after the Awardee’s death. If an Awardee dies when the Awardee has no living beneficiary designated under this Plan, the Company shall allow the executor or administrator of the Awardee’s estate to exercise the Award or, if there is none, the person entitled to exercise the Option under the Awardee’s will or the laws of descent and distribution. In any case, no Award may be exercised after its Expiration Date.

18. Miscellaneous

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18.1 Governing Law . This Plan, the Award Agreements and all other agreements entered into under this Plan, and all actions taken under this Plan or in connection with Awards or Award Shares, shall be governed by the laws of the State of Delaware.

18.2 Determination of Value . Fair Market Value shall be determined as follows:

(a) Listed Stock . If the Shares are traded on any established stock exchange or quoted on a national market system, Fair Market Value shall be the closing sales price for the Shares as quoted on that stock exchange or system for the date the value is to be determined (the “ Value Date ”) as reported in The Wall Street Journal or a similar publication. If no sales are reported as having occurred on the Value Date, Fair Market Value shall be that closing sales price for the last preceding trading day on which sales of Shares are reported as having occurred. If no sales are reported as having occurred during the five trading days before the Value Date, Fair Market Value shall be the closing bid for Shares on the Value Date. If Shares are listed on multiple exchanges or systems, Fair Market Value shall be based on sales or bid prices on the primary exchange or system on which Shares are traded or quoted.

(b) Stock Quoted by Securities Dealer . If Shares are regularly quoted by a recognized securities dealer but selling prices are not reported on any established stock exchange or quoted on a national market system, Fair Market Value shall be the mean between the high bid and low asked prices on the Value Date. If no prices are quoted for the Value Date, Fair Market Value shall be the mean between the high bid and low asked prices on the last preceding trading day on which any bid and asked prices were quoted.

(c) No Established Market . If Shares are not traded on any established stock exchange or quoted on a national market system and are not quoted by a recognized securities dealer, the Administrator (following guidelines established by the Board or Committee) will determine Fair Market Value in good faith. The Administrator will consider the following factors, and any others it considers significant, in determining Fair Market Value: (i) the price at which other securities of the Company have been issued to purchasers other than Employees, Directors, or Consultants, (ii) the Company’s stockholder’s equity, prospective earning power, dividend-paying capacity, and non-operating assets, if any, and (iii) any other relevant factors, including the economic outlook for the Company and the Company’s industry, the Company’s position in that industry, the Company’s goodwill and other intellectual property, and the values of securities of other businesses in the same industry.

18.3 Reservation of Shares . During the term of this Plan, the Company shall at all times reserve and keep available such number of Shares as are still issuable under this Plan.

18.4 Electronic Communications . Any Award Agreement, notice of exercise of an Award, or other document required or permitted by this Plan may be delivered in writing or, to the extent determined by the Administrator, electronically. Signatures may also be electronic if permitted by the Administrator.

18.5 Notices . Unless the Administrator specifies otherwise, any notice to the Company under any Option Agreement or with respect to any Awards or Award Shares shall be in writing (or, if so authorized by Section 17.4, communicated electronically), shall be addressed

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to the Secretary of the Company, and shall only be effective when received by the Secretary of the Company.

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Exhibit 99.2

2004 E MPLOYEE S TOCK P URCHASE P LAN

OF

T HRESHOLD P HARMACEUTICALS , I NC .

As Amended and Restated Effective May 22, 2009

Table of Contents

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THRESHOLD PHARMACEUTICALS, INC.

2004 EMPLOYEE STOCK PURCHASE PLAN

As Amended and Restated Effective May 22, 2009

1. Establishment of Plan.

Threshold Pharmaceuticals, Inc. (the “ Company ”) proposes to grant options for purchase of the Company’s Common Stock (the “ Common Stock ”) to eligible employees of the Company and its Participating Subsidiaries (as hereinafter defined) pursuant to this 2004 Employee Stock Purchase Plan (this “ Plan ”). For the purposes of this Plan, “Parent Corporation” and “Subsidiary” shall have the same meanings as “parent corporation” and “subsidiary corporation” in Sections 424(e) and 424(f), respectively, of the Internal Revenue Code of 1986, as amended (the “ Code ”). “Participating Subsidiaries” are Parent Corporations or Subsidiaries that the Board of Directors of the Company (the “ Board ”) designates from time to time as corporations that shall participate in this Plan. The Company intends this Plan to qualify as an “employee stock purchase plan” under Section 423 of the Code (including any amendments to or replacements of such Section), and this Plan shall be so construed. Any term not expressly defined in this Plan but defined for purposes of Section 423 of the Code shall have the same definition herein.

2. Number of Shares.

Effective May 22, 2009, the total number of shares of Common Stock reserved and available for issuance pursuant to this Plan shall be 411,659 (the “ Share Limit ”). Such Share Limit is subject to adjustments effected in accordance with Section 15 of this Plan. Notwithstanding the foregoing and subject to Section 15, the Share Limit shall automatically increase on January 1, 2010 and January 1 of each year thereafter until and including January 1, 2019 (unless the Plan is terminated earlier in accordance with the provisions hereof) by the  “Annual Increase” which shall consist of a number of shares equal to the least of (i) 100,000, (ii) 1% of the number of shares of all classes of common stock of the Company outstanding on that date, or (iii) a lesser number determined by the Committee, (as hereinafter defined) prior to such January 1, provided, however, that the total number of shares available for issuance under the Plan shall not exceed the initial Share Limit plus the maximum potential cumulative Annual Increase. The Board may at such time as it deems necessary implement a substantially similar plan for employees resident outside the United States ( “Foreign Plan” ) in which case the Share Limit shall be reduced by the number of shares issued under the Foreign Plan. Shares issued under this Plan may consist, in whole or in part, of authorized and unissued shares or treasury shares reacquired in private transactions or open market purchases, but all shares issued under this Plan and the Foreign Plan shall be counted against the Share Limit.

3. Purpose.

The purpose of this Plan is to provide eligible employees of the Company and Participating Subsidiaries with a convenient means of acquiring an equity interest in the Company through payroll deductions, to enhance such employees’ sense of participation in the affairs of the Company and Participating Subsidiaries, and to provide an incentive for continued employment. For the purposes of this Plan, “employee” shall mean any individual who is an employee of the Company or a Participating Subsidiary. Whether an individual qualifies as an employee shall be determined by the Committee, in its sole discretion. The Committee shall be guided by the provisions of Treasury Regulation Section 1.421-7 and Section 3401(c) of the Code and the Treasury Regulations thereunder, with the intent that the Plan cover all “employees” within the meaning of those provisions other than those who are not eligible to participate in the Plan, provided, however, that any determinations regarding whether an individual is an “employee” shall be prospective only, unless otherwise determined by the Committee (as hereinafter defined). Unless the Committee makes a contrary determination, the employees of the Company shall, for all purposes of this Plan, be those individuals who are carried as employees of the Company or a Participating Subsidiary for regular payroll purposes or are on a leave of absence for not more than 90 days. Any inquiries regarding eligibility to participate in the Plan shall be directed to the Committee, whose decision shall be final.

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4. Administration.

This Plan shall be administered by the Compensation Committee of the Board (the “Committee”). Subject to the provisions of this Plan and the limitations of Section 423 of the Code or any successor provision in the Code, all questions of interpretation or application of this Plan shall be determined by the Committee and its decisions shall be final and binding upon all participants. Members of the Committee shall receive no compensation for their services in connection with the administration of this Plan, other than standard fees as established from time to time by the Board for services rendered by Board members serving on Board committees. All expenses incurred in connection with the administration of this Plan shall be paid by the Company.

5. Eligibility.

Any employee of the Company or the Participating Subsidiaries who has been so employed for more than 20 hours per week is eligible to participate in an Offering Period (as hereinafter defined) under this Plan except the following:

(a) employees who are not employed by the Company or a Participating Subsidiary prior to the beginning of such Offering Period or prior to such other time period as specified by the Committee, except that employees who are employed on the effective date of the registration statement filed by the Company with the Securities and Exchange Commission (“SEC”) under the Securities Act of 1933, as amended (the “Securities Act”) registering the initial public offering of the Company’s Common Stock shall be eligible to participate in the first Offering Period under the Plan;

(b) employees who are customarily employed for twenty (20) hours or less per week;

(c) employees who are customarily employed for five (5) months or less in a calendar year;

(d) employees who, together with any other person whose stock would be attributed to such employee pursuant to Section 424(d) of the Code, own stock or hold options to purchase stock possessing five percent (5%) or more of the total combined voting power or value of all classes of stock of the Company or any of its Participating Subsidiaries or who, as a result of being granted an option under this Plan with respect to such Offering Period, would own stock or hold options to purchase stock possessing five percent (5%) or more of the total combined voting power or value of all classes of stock of the Company or any of its Participating Subsidiaries;

(e) individuals who provide services to the Company or any of its Participating Subsidiaries as independent contractors who are reclassified as common law employees for any reason except for federal income and employment tax purposes; and

(f) employees who are citizens or residents of foreign countries for whom such employees’ participation in the Plan would result in a violation under any corporate or securities laws of such foreign country.

6. Offering Dates.

Until changed by resolution of the Committee, the offering periods of this Plan (each, an “Offering Period”) shall be of twenty-four (24) months duration commencing on February 15 and August 15 of each year and ending on February 14 and August 14 of each year; provided, however, that the first such Offering Period shall commence on the first business day on which price quotations for the Company’s Common Stock are available on the Nasdaq National Market (the “First Offering Date”) and shall end on February 14, 2006 (the “First Offering Period”). Except as otherwise provided by the Committee each Offering Period shall be comprised by four six-month “Purchase Periods” except that the first Purchase Period shall commence on the first Offering Date and end February 14, 2005. The first business day of each Offering Period is referred to as the “Offering Date.” The last business day of each Purchase Period is referred to as the “Purchase Date.” The Committee shall have the power to change the Offering Dates, the Purchase Dates, the duration of Offering Periods or Purchase Periods, or the number

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of Purchase Periods within an Offering Period without stockholder approval if such change is announced prior to the relevant Offering Period.

7. Participation in this Plan.

Eligible employees may become participants in an Offering Period under this Plan on the Offering Date, after satisfying the eligibility requirements, by delivering a subscription agreement to the Company prior to such Offering Date, or such other time period as specified by the Committee, provided, however, that all eligible employees employed on or before the First Offering Date shall be automatically enrolled in the First Offering Period. Notwithstanding the foregoing, (i) after the filing of an effective Registration Statement pursuant to Form S-8 for shares under the Plan, an eligible employee may elect to decrease the number of shares of Common Stock that such employee would otherwise be permitted to purchase pursuant to Section 8 below for the First Offering Period and/or purchase shares of Common Stock for the First Offering Period through payroll deductions by delivering a subscription agreement to the Company within thirty (30) days following the First Offering Date; and (ii) the Committee may set a later time for delivering the subscription agreement authorizing payroll deductions for all eligible employees with respect to a given Offering Period. Except as provided above with respect to the First Offering Period, an eligible employee who does not deliver a subscription agreement to the Company after becoming eligible to participate in an Offering Period shall not participate in that Offering Period or any subsequent Offering Period unless such employee enrolls in this Plan by delivering a subscription agreement with the Company prior to such Offering Period, or such other time period as specified by the Committee. Once an employee becomes a participant in an Offering Period by filing a subscription agreement, such employee shall automatically participate in the Offering Period commencing immediately following the last day of the prior Offering Period unless the employee withdraws or is deemed to withdraw from this Plan or terminates further participation in the Offering Period as set forth in Section 12 below. Such participant is not required to file any additional subscription agreement in order to continue participation in this Plan.

8. Grant of Option on Enrollment.

Enrollment by an eligible employee in this Plan with respect to an Offering Period shall constitute the grant (as of the Offering Date) by the Company to such employee of an option to purchase on the Purchase Date up to that number of shares of Common Stock determined by a fraction, the numerator of which is the amount accumulated in such employee’s payroll deduction account during such Purchase Period and the denominator of which is the lower of (i) eighty-five percent (85%) of the fair market value of a share of the Company’s Common Stock on the Offering Date (but in no event less than the par value of a share Common Stock), or (ii) eighty-five percent (85%) of the fair market value of a share of Common Stock on the Purchase Date (but in no event less than the par value of a share of the Company’s Common Stock), provided, however, that for each Purchase Period within the First Offering Period the numerator shall be fifteen percent (15%) of the eligible employee’s compensation for such Purchase Period, unless the employee otherwise elected to decrease the percentage of such employee’s compensation, and provided, further, that the number of shares of Common Stock subject to any option granted pursuant to this Plan shall not exceed the lesser of (x) the maximum number of shares set by the Committee pursuant to Section 11(c) below with respect to the applicable Purchase Date, or (y) the maximum number of shares which may be purchased pursuant to Section 11(b) below with respect to the applicable Purchase Date. The fair market value of a share of the Company’s Common Stock shall be determined as provided in Section 9 below. Notwithstanding the foregoing, in the event of a change in generally accepted accounting principles which would adversely affect the accounting treatment applicable to any current Offering Period, the Committee may make such changes to reduce the number of Shares purchased at the end of Purchase Period or the purchase price paid as are allowable under generally accepted accounting principles and as it deems necessary in the sole discretion of the Committee to avoid or minimize adverse accounting consequences.

9. Purchase Price.

The purchase price per share at which a share of Common Stock shall be sold in any Offering Period shall be eighty-five percent (85%) of the lesser of:

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(a) the fair market value on the Offering Date; or

(b) the fair market value on the Purchase Date.

For the purposes of this Plan, the term “fair market value” means, as of any date, the value of a share of the Company’s Common Stock determined as follows:

(a) if such Common Stock is then quoted on the Nasdaq National Market, its closing price on the Nasdaq National Market on the date of determination as reported in The Wall Street Journal;

(b) if such Common Stock is publicly traded and is then listed on a national securities exchange, its closing price on the date of determination on the principal national securities exchange on which the Common Stock is listed or admitted to trading as reported in The Wall Street Journal; or

(c) if such Common Stock is publicly traded but is not quoted on the Nasdaq National Market nor listed or admitted to trading on a national securities exchange, the average of the closing bid and asked prices on the date of determination as reported in The Wall Street Journal.

Notwithstanding the foregoing, for purposes of the First Offering Date, fair market value shall be the price per share at which shares of the Company’s Common Stock are initially offered for sale to the public by the Company’s underwriters in the initial public offering of the Company’s Common Stock pursuant to a registration statement filed with the SEC under the Securities Act.

10. Payment of Purchase Price; Changes in Payroll Deductions; Issuance of Shares.

(a) The purchase price of the shares is accumulated by regular payroll deductions made during each Offering Period, provided, however, that for the First Offering Period, the purchase price of the shares shall be paid by the eligible employee in cash on each Purchase Date within the First Offering Period unless the eligible employee elects to purchase such shares through payroll deductions, after the filing of an effective Form S-8 registration statement pursuant to the second sentence of Section 7 above, within thirty (30) days following the First Offering Period. The deductions are made as a percentage of the participant’s compensation in one percent (1%) increments, not less than one percent (1%), nor greater than fifteen percent (15%), or such lower limit set by the Committee. Compensation shall mean all W-2 cash compensation, including, but not limited to, base salary, wages, bonuses, incentive compensation, commissions, overtime, shift premiums, plus draws against commissions, provided, however that compensation shall not include any long term disability or workman’s compensation payments, car allowances, relocation payments or expense reimbursements and further provided, however, that for purposes of determining a participant’s compensation, any election by such participant to reduce his or her regular cash remuneration under Sections 125 or 401(k) of the Code shall be treated as if the participant did not make such election. Payroll deductions shall commence on the first payday of the Offering Period and shall continue to the end of the Offering Period unless sooner altered or terminated as provided in this Plan.

(b) A participant may increase or decrease the rate of payroll deductions during an Offering Period by filing with the Company a new authorization for payroll deductions, in which case the new rate shall become effective for the next payroll period commencing after the Company’s receipt of the authorization and shall continue for the remainder of the Offering Period unless changed as described below. Such change in the rate of payroll deductions may be made at any time during an Offering Period, but not more than one (1) change may be made effective during any Purchase Period. A participant may increase or decrease the rate of payroll deductions for any subsequent Offering Period by filing with the Company a new authorization for payroll deductions prior to the beginning of such Offering Period, or such other time period as specified by the Committee.

(c) A participant may reduce his or her payroll deduction percentage to zero during an Offering Period by filing with the Company a request for cessation of payroll deductions. Such reduction shall be effective beginning with the next payroll period after the Company’s receipt of the request and no further payroll deductions

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shall be made for the duration of the Offering Period. Payroll deductions credited to the participant’s account prior to the effective date of the request shall be used to purchase shares of Common Stock of the Company in accordance with Section (e) below. A participant may not resume making payroll deductions during the Offering Period in which he or she reduced his or her payroll deductions to zero.

(d) All payroll deductions made for a participant are credited to his or her account under this Plan and are deposited with the general funds of the Company. No interest accrues on the payroll deductions. All payroll deductions received or held by the Company may be used by the Company for any corporate purpose, and the Company shall not be obligated to segregate such payroll deductions.

(e) On each Purchase Date, for so long as this Plan remains in effect and provided that the participant has not submitted a signed and completed withdrawal form before that date, which notifies the Company that the participant wishes to withdraw from that Offering Period under this Plan and have all payroll deductions accumulated in the account maintained on behalf of the participant, as of that date returned to the participant, the Company shall apply the funds then in the participant’s account to the purchase of whole shares of Common Stock reserved under the option granted to such participant with respect to the Offering Period to the extent that such option is exercisable on the Purchase Date. The purchase price per share shall be as specified in Section 9 of this Plan. Any cash remaining in a participant’s account after such purchase of shares shall be refunded to such participant in cash, without interest, provided, however, that any amount remaining in such participant’s account on a Purchase Date which is less than the amount necessary to purchase a full share of Common Stock shall be carried forward, without interest, into the next Purchase Period or Offering Period, as the case may be. In the event that this Plan has been oversubscribed, all funds not used to purchase shares on the Purchase Date shall be returned to the participant, without interest. No Common Stock shall be purchased on a Purchase Date on behalf of any employee whose participation in this Plan has terminated prior to such Purchase Date.

(f) As soon as practicable after the Purchase Date, the Company shall issue shares for the participant’s benefit representing the shares purchased upon exercise of his or her option.

(g) During a participant’s lifetime, his or her option to purchase shares hereunder is exercisable only by him or her. The participant shall have no interest or voting rights in shares covered by his or her option until such option has been exercised.

11. Limitations on Shares to be Purchased.

(a) No participant shall be entitled to purchase stock under this Plan at a rate which, when aggregated with his or her rights to purchase stock under all other employee stock purchase plans of the Company or any Subsidiary, exceeds $25,000 in fair market value, determined as of the Offering Date (or such other limit as may be imposed by the Code) for each calendar year in which an Offering Period is outstanding, a Purchase Date occurs and the employee participates in this Plan. This limit means that the maximum purchase price for shares purchased during a calendar year is $21,250 assuming a 15% discount pursuant to Section 9. The Company shall automatically suspend the payroll deductions of any participant as necessary to enforce such limit provided that when the Company automatically resumes such payroll deductions, the Company must apply the rate in effect immediately prior to such suspension.

(b) No participant shall be entitled to purchase more than the Maximum Share Amount (as defined below) on any single Purchase Date. Prior to the commencement of any Offering Period or prior to such earlier time period as specified by the Committee, the Committee may, in its sole discretion, set a maximum number of shares which may be purchased by any employee at any single Purchase Date (hereinafter the “Maximum Share Amount”). Effective with the first Offering Period commencing after the May 22, 2009 amendment and restatement of the Plan, the Maximum Share Amount shall be 3,000 shares. If a new Maximum Share Amount is set, then all participants must be notified of such Maximum Share Amount prior to the commencement of the next Offering Period. The Maximum Share Amount shall continue to apply with respect to all succeeding Purchase Dates and Offering Periods unless revised by the Committee as set forth above.

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(c) If the number of shares to be purchased on a Purchase Date by all employees participating in this Plan exceeds the number of shares then available for issuance under this Plan, then the Company shall make a pro rata allocation of the remaining shares in as uniform a manner as shall be reasonably practicable and as the Committee shall determine to be equitable. In such event, the Company shall give written notice of such reduction of the number of shares to be purchased under a participant’s option to each participant affected.

(d) Any payroll deductions accumulated in a participant’s account which are not used to purchase stock due to the limitations in this Section 11 shall be returned to the participant as soon as practicable after the end of the applicable Purchase Period, without interest.

12. Withdrawal.

(a) Each participant may withdraw from an Offering Period under this Plan by signing and delivering to the Company a written notice to that effect on a form provided for such purpose. Such withdrawal may be elected at any time prior to the end of an Offering Period, or such other time period as specified by the Committee.

(b) Upon withdrawal from this Plan, the accumulated payroll deductions shall be returned to the withdrawn participant, without interest, and his or her interest in this Plan shall terminate. In the event a participant voluntarily elects to withdraw from this Plan, he or she may not resume his or her participation in this Plan during the same Offering Period, but he or she may participate in any Offering Period under this Plan which commences on a date subsequent to such withdrawal by filing a new authorization for payroll deductions in the same manner as set forth in Section 7 above for initial participation in this Plan.

(c) If the Fair Market Value on the first day of the current Offering Period in which a participant is enrolled is higher than the Fair Market Value on the first day of the immediately succeeding Offering Period, the Company shall automatically enroll such participant in the subsequent Offering Period at the same rate of payroll deductions (and if the Offering Period is comprised of two or more Purchase Periods, the Company shall automatically withdraw the participant from the preceding Offering Period). Any funds accumulated in a participant’s account prior to the first day of such subsequent Offering Period shall be applied to the purchase of shares on the Purchase Date immediately prior to the first day of such subsequent Offering Period, if any.

13. Termination of Employment.

Termination of a participant’s employment for any reason, including retirement, death or the failure of a participant to remain an eligible employee of the Company or of a Participating Subsidiary, shall immediately terminate his or her participation in this Plan. In such event, the payroll deductions credited to the participant’s account shall be returned to him or her or, in the case of his or her death, to his or her legal representative, without interest. For purposes of this Section 13, an employee shall not be deemed to have terminated employment or failed to remain in the continuous employ of the Company or of a Participating Subsidiary in the case of sick leave, military leave, or any other leave of absence approved by the Board, provided, however that such leave is for a period of not more than ninety (90) days or reemployment upon the expiration of such leave is guaranteed by contract or statute.

14. Return of Payroll Deductions.

In the event a participant’s interest in this Plan is terminated by withdrawal, termination of employment or otherwise, or in the event this Plan is terminated by the Board, the Company shall deliver to the participant all payroll deductions credited to such participant’s account. No interest shall accrue on the payroll deductions of a participant in this Plan.

15. Capital Changes.

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Subject to any required action by the stockholders of the Company, the number and type of shares of Common Stock covered by each option under this Plan which has not yet been exercised and the number and type of shares of Common Stock which have been authorized for issuance under this Plan, including the Annual Increase, but have not yet been placed under option (collectively, the “Reserves”), the Maximum Share Amount, as well as the price per share of Common Stock covered by each option under this Plan which has not yet been exercised, shall be proportionately adjusted for any increase or decrease in the number of issued and outstanding shares of Common Stock of the Company resulting from a stock split or the payment of a stock dividend (but only on the Common Stock), any other increase or decrease in the number of issued and outstanding shares of Common Stock effected without receipt of any consideration by the Company or other change in the corporate structure or capitalization affecting the Company’s present Common Stock, provided, however, that conversion of any convertible securities of the Company shall not be deemed to have been “effected without receipt of consideration.” Such adjustment shall be made by the Committee, whose determination shall be final, binding and conclusive. Except as expressly provided herein, no issue by the Company of shares of stock of any class, or securities convertible into shares of stock of any class, shall affect, and no adjustment by reason thereof shall be made with respect to, the number or price of shares of Common Stock subject to an option.

In the event of the proposed dissolution or liquidation of the Company, the Offering Period shall terminate immediately prior to the consummation of such proposed action, unless otherwise provided by the Committee. The Committee may, in the exercise of its sole discretion in such instances, declare that this Plan shall terminate as of a date fixed by the Committee and give each participant the right to purchase shares under this Plan prior to such termination. In the event of (i) a merger or consolidation in which the Company is not the surviving corporation (other than a merger or consolidation with a wholly-owned subsidiary, a reincorporation of the Company in a different jurisdiction, or other transaction in which there is no substantial change in the stockholders of the Company or their relative stock holdings and the options under this Plan are assumed, converted or replaced by the successor corporation, which assumption shall be binding on all participants), (ii) a merger in which the Company is the surviving corporation but after which the stockholders of the Company immediately prior to such merger (other than any stockholder that merges, or which owns or controls another corporation that merges, with the Company in such merger) cease to own their shares or other equity interest in the Company, (iii) the sale of all or substantially all of the assets of the Company, or (iv) the acquisition, sale, or transfer of more than 50% of the outstanding shares of the Company by tender offer or similar transaction (each, a “Corporate Transaction”), each option under the Plan shall be assumed by such surviving corporation, unless the Committee, in the exercise of its sole discretion and in lieu of such assumption, determines to shorten the Offering Period then in progress by setting a new Purchase Date (the “New Purchase Date”). If the Committee shortens the Offering Period then in progress in the event of a Corporate Transaction, the Committee shall notify each participant in writing at least ten (10) business days prior to the New Purchase Date, that the Purchase Date for the participant’s option has been changed to the New Purchase Date and that either :

(a) the participant’s option will be exercised automatically on the New Purchase Date, unless prior to such date the participant has withdrawn from the Offering Period as provided in Section 12; or

(b) the Company shall pay to the participant on the New Purchase Date an amount in cash, cash equivalents, or property as determined by the Committee that is equal to the difference in Fair Market Value of the shares subject to the option and the Purchase Price due had the participant’s option been exercised automatically under Section 15(a) above.

The Plan shall continue with regard to Offering Periods that commenced prior to the closing of the proposed transaction and shares shall be purchased based on the Fair Market Value of the surviving corporation’s stock on each Purchase Date, unless otherwise provided by the Committee. For purposes of this Section 15, an option granted under the Plan shall be deemed to be assumed if, in connection with the Corporate Transaction, the option is replaced with a comparable option with respect to shares of capital stock of the surviving corporation or parent thereof. The determination of option comparability shall be made by the Committee prior to the Corporate Transaction and its determination shall be final, binding and conclusive on all persons.

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The Committee may, if it so determines in the exercise of its sole discretion, also make provision for adjusting the Reserves, the Maximum Share Amount, as well as the price per share of Common Stock covered by each outstanding option, in the event that the Company effects one or more reorganizations, recapitalizations, rights offerings or other increases or reductions of shares of its outstanding Common Stock, or in the event of the Company being consolidated with or merged into any other corporation.

16. Nonassignability.

Neither payroll deductions credited to a participant’s account nor any rights with regard to the exercise of an option or to receive shares under this Plan may be assigned, transferred, pledged or otherwise disposed of in any way (other than by shall, the laws of descent and distribution or as provided in Section 23 below) by the participant. Any such attempt at assignment, transfer, pledge or other disposition shall be void and without effect.

17. Reports.

Individual accounts shall be maintained for each participant in this Plan. Each participant shall receive, as soon as practicable after the end of each Purchase Period, a report of his or her account setting forth the total payroll deductions accumulated, the number of shares purchased, the per share price thereof and the remaining cash balance, if any, carried forward to the next Purchase Period or Offering Period, as the case may be.

18. Notice of Disposition.

Each participant shall notify the Company in writing if the participant disposes of any of the shares purchased in any Offering Period pursuant to this Plan if such disposition occurs within two (2) years from the Offering Date or within one (1) year from the Purchase Date on which such shares were purchased (the “Notice Period”). The Company may, at any time during the Notice Period, place a legend or legends on any certificate representing shares acquired pursuant to this Plan requesting the Company’s transfer agent to notify the Company of any transfer of the shares. The obligation of the participant to provide such notice shall continue notwithstanding the placement of any such legend on the certificates.

19. No Rights to Continued Employment.

Neither this Plan nor the grant of any option hereunder shall confer any right on any employee to remain in the employ of the Company or any Participating Subsidiary, or restrict the right of the Company or any Participating Subsidiary to terminate such employee’s employment.

20. Equal Rights and Privileges.

All eligible employees shall have equal rights and privileges with respect to this Plan so that this Plan qualifies as an “employee stock purchase plan” within the meaning of Section 423 or any successor provision of the Code and the related regulations. Any provision of this Plan which is inconsistent with Section 423 or any successor provision of the Code shall, without further act or amendment by the Company, the Committee or the Board, be reformed to comply with the requirements of Section 423. This Section 20 shall take precedence over all other provisions in this Plan.

21. Notices.

All notices or other communications by a participant to the Company under or in connection with this Plan shall be deemed to have been duly given when received in the form specified by the Company at the location, or by the person, designated by the Company for the receipt thereof.

22. Term; Stockholder Approval.

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After this Plan is adopted by the Board, this Plan shall become effective on the First Offering Date (as defined above). This Plan shall be approved by the stockholders of the Company, in any manner permitted by applicable corporate law, within twelve (12) months before or after the date this Plan is adopted by the Board. No purchase of shares pursuant to this Plan shall occur prior to such stockholder approval. This Plan shall continue until the earlier to occur of (a) termination of this Plan by the Board (which termination may be effected by the Board at any time), (b) issuance of all of the shares of Common Stock reserved for issuance under this Plan, or (c) ten (10) years from the May 22, 2009 amendment and restatement of the Plan.

23. Designation of Beneficiary.

(a) A participant may file a written designation of a beneficiary who is to receive any shares and cash, if any, from the participant’s account under this Plan in the event of such participant’s death subsequent to the end of a Purchase Period but prior to delivery to him of such shares and cash. In addition, a participant may file a written designation of a beneficiary who is to receive any cash from the participant’s account under this Plan in the event of such participant’s death prior to a Purchase Date.

(b) Such designation of beneficiary may be changed by the participant at any time by written notice. In the event of the death of a participant and in the absence of a beneficiary validly designated under this Plan who is living at the time of such participant’s death, the Company shall deliver such shares or cash to the executor or administrator of the estate of the participant, or if no such executor or administrator has been appointed (to the knowledge of the Company), the Company, in its discretion, may deliver such shares or cash to the spouse or to any one or more dependents or relatives of the participant, or if no spouse, dependent or relative is known to the Company, then to such other person as the Company may designate.

24. Conditions Upon Issuance of Shares; Limitation on Sale of Shares.

Shares shall not be issued with respect to an option unless the exercise of such option and the issuance and delivery of such shares pursuant thereto shall comply with all applicable provisions of law, domestic or foreign, including, without limitation, the Securities Act, the Securities Exchange Act of 1934, as amended, the rules and regulations promulgated thereunder, and the requirements of any stock exchange or automated quotation system upon which the shares may then be listed, and shall be further subject to the approval of counsel for the Company with respect to such compliance.

25. Applicable Law.

The Plan shall be governed by the substantive laws (excluding the conflict of laws rules) of the State of Delaware.

26. Amendment or Termination.

The Board may at any time amend, terminate or extend the term of this Plan, except that any such termination cannot affect options previously granted under this Plan, nor may any amendment make any change in an option previously granted which would adversely affect the right of any participant, nor may any amendment be made without approval of the stockholders of the Company obtained in accordance with Section 22 above within twelve (12) months of the adoption of such amendment (or earlier if required by Section 22) if such amendment would:

(a) increase the number of shares that may be issued under this Plan; or

(b) change the designation of the employees (or class of employees) eligible for participation in this Plan.

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Notwithstanding the foregoing, the Board may make such amendments to the Plan as the Board determines to be advisable and which do not cause unfavorable accounting treatment, including changes with respect to current Offering Periods or Purchase Period, if the continuation of the Plan or any Offering Period would result in financial accounting treatment for the Plan that is different from the financial accounting treatment in effect on the date this Plan is adopted by the Board; provided, however, that any changes to the number of Purchase Periods within an Offering Period or the duration of Purchase Periods shall take effect with respect to the first Offering Period that commences following any such amendment.

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