2000 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

2.                                            DEFINITIONS.

(a)                              “ Affiliate ” means, at the time of determination, any “parent” or “subsidiary” of the Company as such terms are defined in Rule 405 of the Securities Act.  The Board shall have the authority to determine the time or times at which “parent” or “subsidiary” status is determined within the foregoing definition.

(b)                              “ Annual Grant” means an Option granted annually to all Non-Employee Directors who meet the criteria specified in subsection 6(b) of the Plan.

(c)                              “ Annual Meeting” means the annual meeting of the stockholders of the Company.

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

(e)                              A “Change in Control,” with respect to Options granted on or after the effective date of the Plan, will be deemed to have occurred upon the first to occur of an event set forth in any one of the following paragraphs:

(i)                                     the acquisition (other than from the Company, by any person (as such term is defined in Section 13(c) or 14(d) of the Exchange Act of beneficial ownership (within the meaning of Rule 13d-3 promulgated under the Exchange Act) of fifty (50%) or more of the combined voting power of the Company’s then outstanding voting securities; or

(ii)                                 the closing of:

( a )                                a merger or consolidation involving the Company if the stockholders of the Company, immediately before such merger or consolidation, do not, as a result of such merger or consolidation, own, directly or indirectly, more than fifty percent (50%) of the combined voting power of the then outstanding voting securities of the corporation resulting from such merger or consolidation in substantially the same proportion as their ownership of the combined voting power of the voting securities of the Company outstanding immediately before such merger or consolidation; or

( b )                                 a complete liquidation or dissolution of the Company or an agreement for the sale or other disposition of all or substantially all of the assets of the Company.

Notwithstanding the foregoing, a Change in Control shall not be deemed to occur solely because fifty percent (50%) or more of the combined voting power of the Company’s then outstanding securities is acquired by (i) a trustee or other fiduciary holding securities under one or more

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employee benefit plans maintained by the Company or any of its subsidiaries or (ii) any corporation which, immediately prior to such acquisition, is owned directly or indirectly by the stockholders of the Company in the same proportion as their ownership of stock in the Company immediately prior to such acquisition.

For the avoidance of doubt, the term Change in Control shall not include a sale of assets, merger or other transaction effected exclusively for the purpose of changing the domicile of the Company.

Notwithstanding the foregoing or any other provision of this Plan, the definition of Change in Control (or any analogous term) in an individual written agreement between the Company or any Affiliate and the Optionholder shall supersede the foregoing definition with respect to Options subject to such agreement; provided, however, that if no definition of Change in Control or any analogous term is set forth in such an individual written agreement, the foregoing definition shall apply.

(f)                                “ Code ” means the Internal Revenue Code of 1986, as amended.

(g)                             “ Common Stock ” means the common stock of the Company.

(h)                             “ Company ” means Rigel Pharmaceuticals, Inc., a Delaware corporation.

(i)                                “ Consultant ” means any person, including an advisor, (i) engaged by the Company or an Affiliate to render consulting or advisory services and who is compensated for such services or (ii) who is a member of the Board of Directors of an Affiliate. However, the term “Consultant” shall not include either Directors of the Company who are not compensated by the Company for their services as Directors or Directors of the Company who are merely paid a director’s fee by the Company for their services as Directors.

(j)                                “ Continuous Service ” means that the Optionholder’s service with the Company or an Affiliate, whether as an Employee, Director or Consultant, is not interrupted or terminated. The Optionholder’s Continuous Service shall not be deemed to have terminated merely because of a change in the capacity in which the Optionholder renders service to the Company or an Affiliate as an Employee, Consultant or Director or a change in the entity for which the Optionholder renders such service, provided that there is no interruption or termination of the Optionholder’s service. For example, a change in status without interruption from a Non-Employee Director of the Company to a Consultant of an Affiliate or an Employee of the Company will not constitute an interruption of Continuous Service. The Board or the chief executive officer of the Company, in that party’s sole discretion, may determine whether

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Continuous Service shall be considered interrupted in the case of any leave of absence approved by that party, including sick leave, military leave or any other personal leave.

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

(l)                                “ Disability” means the permanent and total disability of a person within the meaning of Section 22(e)(3) of the Code.

(m)                          “ Employee ” means any person employed by the Company or an Affiliate. Mere service as a Director or payment of a director’s fee by the Company or an Affiliate shall not be sufficient to constitute “employment” by the Company or an Affiliate.

(n)                             “ Exchange Act ” means the Securities Exchange Act of 1934, as amended.

(o)                              “ Fair Market Value ” means, as of any date, the value of the Common Stock determined as follows:

(i)                           If the Common Stock is listed on any established stock exchange or traded on the Nasdaq National Market or the Nasdaq SmallCap Market, the Fair Market Value of a share of Common Stock shall be the closing sales price for such stock (or the closing bid, if no sales were reported) as quoted on such exchange or market (or the exchange or market with the greatest volume of trading in the Common Stock) on the last market trading day prior to the day of determination, as reported in The Wall Street Journal or such other source as the Board deems reliable.

(ii)                       In the absence of such markets for the Common Stock, the Fair Market Value shall be determined in good faith by the Board.

(p)                              “ Initial Grant” means an Option granted to a Non-Employee Director who meets the criteria specified in subsection 6(a) of the Plan.

(q)                              “ IPO Date” means the effective date of the initial public offering of the Common Stock.

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(r)                              “ Non-Employee Director ” means a Director who is not an Employee.

(s)                              “ Nonstatutory Stock Option ” means an Option not intended to qualify as an incentive stock option within the meaning of Section 422 of the Code and the regulations promulgated thereunder.

(t)                                “ Officer ” means a person who is an officer of the Company within the meaning of Section 16 of the Exchange Act and the rules and regulations promulgated thereunder.

(u)                             “ Option ” means a Nonstatutory Stock Option granted pursuant to the Plan.

(v)                               “ Option Agreement ” means a written agreement between the Company and an Optionholder evidencing the terms and conditions of an individual Option grant. Each Option Agreement shall be subject to the terms and conditions of the Plan.

(w)                            “ Optionholder ” means a person to whom an Option is granted pursuant to the Plan or, if applicable, such other person who holds an outstanding Option.

(x)                              “ Plan ” means this Rigel Pharmaceuticals, Inc. 2000 Non-Employee Directors’ Stock Option Plan.

(y)                              “ Rule 16b-3 ” means Rule 16b-3 promulgated under the Exchange Act or any successor to Rule 16b-3, as in effect from time to time.

(z)                              “ Securities Act ” means the Securities Act of 1933, as amended.

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3.                                            ADMINISTRATION.

(a)                              Administration by Board . The Board shall administer the Plan. The Board may not delegate administration of the Plan to a committee.

(b)                              Powers of Board . The Board shall have the power, subject to, and within the limitations of, the express provisions of the Plan:

(i)                           To determine the provisions of each Option to the extent not specified in the Plan.

(ii)                       To construe and interpret the Plan and Options granted under it, and to establish, amend and revoke rules and regulations for its administration. The Board, in the exercise of this power, may correct any defect, omission or inconsistency in the Plan or in any Option Agreement, in a manner and to the extent it shall deem necessary or expedient to make the Plan fully effective.

(iii)                   To amend the Plan or an Option as provided in Section 12.

(iv)                      To terminate or suspend the Plan as provided in Section 13.

(v)                          Generally, to exercise such powers and to perform such acts as the Board deems necessary or expedient to promote the best interests of the Company that are not in conflict with the provisions of the Plan.

(c)                              Effect of Board’s Decision. All determinations, interpretations and constructions made by the Board in good faith shall not be subject to review by any person and shall be final, binding and conclusive on all persons.

(d)                              Cancellation and Re-Grant of Options . Notwithstanding anything to the contrary in the Plan, neither the Board nor any Committee shall have the authority to: (i) reprice any outstanding Option under the Plan, (ii) cancel and re-grant any outstanding Option under the Plan, or (iii) effect any other action that is treated as a repricing under generally accepted accounting principles unless, in each case, the stockholders of the Company have approved such an action within twelve (12) months prior to such an event.

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4.                                            SHARES SUBJECT TO THE PLAN.

(a)                              Share Reserve . Subject to the provisions of Section 11 relating to adjustments upon changes in the Common Stock, the Common Stock that may be issued pursuant to Options shall not exceed in the aggregate 435,000 shares of Common Stock, which number consists of (i) 33,333 shares of Common stock initially reserved for issuance under the Plan plus (ii) 66,667 shares of Common stock approved by the Board in April 2003 and subsequently approved by the Company’s stockholders plus (iii) 225,000 shares of Common Stock approved by the Board in April 2005 and subsequently approved by the Company’s stockholders plus (iv) 110,000 shares of Common Stock approved by the Board in January 2007 and subsequently approved by the Company’s stockholders.

(b)                              Reversion of Shares to the Share Reserve . If any Option shall for any reason expire or otherwise terminate, in whole or in part, without having been exercised in full, the shares of Common Stock not acquired under such Option shall revert to and again become available for issuance under the Plan. If any shares subject to an Option are not delivered to an Optionholder because the Option is exercised through a reduction of shares subject to the Option ( i.e ., “net exercised”), the number of shares that are not delivered to the Optionholder shall not remain available for issuance under the Plan. If any shares subject to an Option are not delivered to an Optionholder because such shares are withheld in satisfaction of the withholding of taxes incurred in connection with the exercise of an Option, the number of shares that are not delivered to the Optionholder shall not remain available for subsequent issuance under the Plan. If the exercise price of any Option is satisfied by tendering shares of Common Stock held by the Optionholder (either by actual delivery or attestation), then the number of shares so tendered shall not remain available for subsequent issuance under the Plan.

(c)                              Source of Shares . The shares of Common Stock subject to the Plan may be unissued shares or reacquired shares, bought on the market or otherwise.

5.                                            ELIGIBILITY.

The Options as set forth in section 6 automatically shall be granted under the Plan to all Non-Employee Directors who meet the specified criteria.

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6.                                            NON-DISCRETIONARY GRANTS.

(a)                              Initial Grants. Without any further action o