Subject to such additional shares of Stock as shall be available for issuance under the Plan pursuant to Section 4.2, and subject to adjustment pursuant to Section 17, the maximum number of shares of Stock available for issuance under the Plan shall be equal to 65 million shares, plus the number of shares of Stock subject to awards outstanding under the Prior Plan as of the Effective Date which thereafter terminate by expiration, forfeiture, cancellation or otherwise without the issuance of such shares.

Agreement Subject to the Plan. This Agreement is subject to the provisions of the Plan and shall be interpreted in accordance therewith. In the event that the

Stock Subject to the Plan. Subject to adjustment upon changes in capitalization of the Company as provided in Section 14, the maximum aggregate number of Shares that may be subject to Awards and sold under the Plan will be equal to # 1,000,000 Shares, plus # any Shares subject to awards granted under the Tocagen, Inc. 2009 Equity Incentive Plan, the Tocagen, Inc. 2017 Equity Incentive Plan, and the Forte Biosciences Inc. 2018 Equity Incentive Plan that, after the date of stockholder approval of the Plan, expire or otherwise terminate without having been exercised or issued in full, are tendered to or withheld by the Company for payment of an exercise price or for tax withholding obligations, or are forfeited to or repurchased by the Company due to failure to vest, with the maximum number of Shares to be added to the Plan pursuant to clause (b) equal to 1,102,341. In addition, Shares may become available for issuance under Section 3.2. The Shares may be authorized but unissued, or reacquired Common Stock.

Subject to adjustment as provided in Section 13 of the Plan, a total of 250,000 shares of Company Stock may be issued pursuant to Awards under the Plan. Subject to adjustment as provided in Section 13, no more than an aggregate of 250,000 shares of Company Stock may be issued pursuant to the exercise of Incentive Stock Options granted under the Plan (including shares issued pursuant to the exercise of Incentive Stock Options that are the subject to disqualifying dispositions within in the meaning of Sections 421 and 422 of the Code).

Restricted Stock Subject to Plan. This Award is subject to the Plan as approved by the Company’s stockholders and as may thereafter be amended or modified in accordance with its terms. The terms and provisions of the Plan as it may be amended from time to time are hereby incorporated herein by reference. In the event of a conflict between any term or provision contained herein and a term or provision of the Plan, the applicable terms and provisions of the Plan will govern and prevail.

Subject to adjustment as provided below, the total number of shares of Stock reserved and available for issuance in connection with the Plan is Ten Million Four Hundred Ninety Thousand Seven Hundred Eighty-Four (10,490,784). Any Stock issued hereunder may consist, in whole or in part, of authorized and unissued shares or treasury shares. If there is a merger, reorganization, consolidation, recapitalization, share dividend, share split, reverse split, combination of shares or other change in corporate structure of the Company affecting the Stock, such substitution or adjustment shall be made in the aggregate number of shares of Stock reserved for issuance under the Plan, and in the number of shares deemed to be held in any Account, as may be approved by the Committee in its sole discretion.

Plan Adoption Subject to Qualification. Notwithstanding any other provision of the Plan, the adoption of the Plan and the execution of the Trust Agreement are conditioned upon their being determined initially by the Internal Revenue Service to meet the qualification requirements of Section 401(a) of the Code, so that the Employers may deduct currently for federal income tax purposes their contributions to the Trust and so that the Participants may exclude the contributions from their gross income and recognize income only when they receive benefits. In the event that this Plan is held by the Internal Revenue Service not to qualify initially under [Section 401(a)], the Plan may be amended retroactively to the earliest date permitted by U.S. Treasury Regulations in order to secure qualification under [Section 401(a)]. If this Plan is held by the Internal Revenue Service not to qualify initially under [Section 401(a)] either as originally adopted or as amended, each Employer’s contributions to the Trust under this Plan (including any earnings thereon) shall be returned to it and this Plan shall be terminated. In the event that this Plan is amended after its initial qualification and the Plan as amended is held by the Internal Revenue Service not to qualify under [Section 401(a)], the amendment may be modified retroactively to the earliest date permitted by U.S. Treasury Regulations in order to secure approval of the amendment under [Section 401(a)]. In addition, reversions of Employer contributions (including earnings or losses attributable thereto) are permitted within one year after the applicable determination date, if the reversion is due to a good faith mistake of fact.

STOCK SUBJECT TO THE PLAN. The Committee may issue under this Plan not more than 0.60% in any one calendar year of the common stock of the Corporation outstanding at the beginning of such year. Such common stock is herein sometimes referred to either as “book value shares” or as “market value shares.” The distribution of shares pursuant to this Plan may be made either from authorized and unissued shares or from Treasury shares, as determined by the Committee. All shares issued in accordance with the Plan shall be fully paid and non-assessable shares and free from preemptive rights.

Shares Subject to This Plan. Stock with respect to which Options are granted or issued under this Plan shall be authorized but unissued or reacquired Shares of the Company’s Common Stock. The aggregate number of Shares which may be issued under this Plan shall not exceed three million five hundred thousand (3,500,000) Shares, subject to adjustment under Section 9.

Severability; Provisions Subject to Applicable Law. All provisions of this Agreement shall be applicable only to the extent that they do not violate any applicable law, and are intended to be limited to the extent necessary so that they will not render this Agreement invalid, illegal or unenforceable under any applicable law. If any provision of this Agreement or any application thereof shall be held to be invalid, illegal or unenforceable, the validity, legality and enforceability of other provisions of this Agreement or of any other application of such provision shall in no way be affected thereby.