Exercise of Option. This Option may be exercised in whole or in part at any time or times prior to its expiration; provided that the first exercise of this Option shall not occur before the fourth anniversary of the date on which the Option was granted. Notwithstanding the foregoing, if the Participant’s employment with the Corporation or a Subsidiary Company is terminated by reason of the Participant’s Retirement or death before the fourth anniversary of the date on which the Option was granted, the Participant (or, in the case of death, the Participant’s Beneficiary) may first exercise this Option on the later of the first anniversary of the date on which this Option was granted or the effective date of the Participant’s Retirement or death. Notice of the exercise of all or any part of this Option shall be given in the manner prescribed by the Secretary of the Corporation. Such notice shall be irrevocable, shall specify the number of shares to be purchased and the purchase price to be paid therefore, and must be accompanied by the payment of the purchase price as provided in paragraph 3(c) herein. Upon the exercise of such Option, the Common Stock purchased will be distributed.

Exercise of Option. The times, circumstances and conditions under which an Option shall be exercisable shall be determined by the Committee in its sole discretion and set forth in the Award Agreement. Unless otherwise determined by the Committee and set forth in the Award Agreement, each Option granted to an Employee for an eight-year term shall vest and become exercisable as to ten (10%) percent of the Shares covered thereby on the third anniversary of Continuous Service after the Grant Date, as to twenty (20%) percent of the Shares covered thereby on the fourth anniversary of Continuous Service after the Grant Date, as to twenty (20%) percent of the Shares covered thereby on the fifth anniversary of Continuous Service after the Grant Date, as to twenty-five (25%) percent of the Shares covered thereby on the sixth anniversary of Continuous Service after the Grant Date, as to fifteen (15%) percent of the Shares covered thereby on the seventh anniversary of Continuous Service after the Grant Date, and as to ten (10%) percent of the Shares covered thereby on the eighth anniversary of Continuous Service after the Grant Date. Each Option granted for a five-year term shall vest and become exercisable at such time or times as shall be determined by the Committee and set forth in the Award Agreement. The Committee shall have the discretion to determine whether and to what extent the vesting of Options shall be tolled during any unpaid leave of absence; provided, however, that in the absence of such determination, vesting of Options shall be tolled during any such leave approved by the Company.

Option Exercise Price. The exercise price per Share subject to each Option shall be set by the Administrator, but shall not be less than one hundred percent (100%) of the Fair Market Value of a Share on the date the Option is granted (or, as to Incentive Stock Options, on the date the Option is modified, extended or renewed for purposes of Section 424(h) of the Code). In addition, in the case of Incentive Stock Options granted to a Greater Than 10% Stockholder, such price shall not be less than one hundred ten percent (110%) of the Fair Market Value of a Share on the date the Option is granted (or the date the Option is modified, extended or renewed for purposes of Section 424(h) of the Code).

Exercise of Option. An Option shall be exercisable at such times and be subject to such restrictions and conditions as the Committee shall in each instance approve, which terms and restrictions need not be the same for each grant or for each Participant, except that no Option shall be exercisable within one (1) year from its Grant Date, except in the case of the death of the Participant.

Exercise of Option. Effective as of the Exercise Effective Date set forth in the signature page below, the undersigned individual (“Participant”) hereby elects to exercise Participant’s option (the “Option”) to purchase the number of shares of the Common Stock reflected in the signature page below (the “Shares”) of DatChat, Inc. (the “Company”) under and pursuant to, and be subject to the terms and conditions of, the 2021 Equity Incentive Plan (the “Plan”), the Stock Option Agreement and this Exercise Notice.

Exercise of Option. Effective as of today, the undersigned ("Optionee") hereby elects to exercise Optionee's option to purchase ​ shares of the Common Stock (the "Shares") of Assembly Biosciences, Inc. (the "Company") under and pursuant to the Company's Amended and Restated 2014 Stock Incentive Plan, as amended (the "Plan") and the Notice of Stock Option Grant dated ​, 20​ with its attached Stock Option Agreement (the "Option Agreement"). The purchase price for the Shares shall be ​ as required by the Option Agreement. Optionee herewith delivers to the Company the full Exercise Price for the Shares.

Exercise of Option. Once vested, the Participant may exercise this Option, in whole or in part, at any time during the term as specified above but not after ten (10) years from the Date of Grant; provided, that if the Participant dies, this Option, if vested, may be exercised within three (3) years after

Exercise of Option. This Option is exercisable as follows:

Exercise of Option. Effective as of today, , the undersigned (the “Optionee”) hereby elects to exercise Optionee’s option to purchase shares of the Common Stock (the “Shares”) of Gritstone Oncology, Inc., a Delaware corporation (the “Company”), under and pursuant to the Gritstone Oncology, Inc. 2015 Equity Incentive Plan, as amended from time to time (the “Plan”), and the Stock Option Grant Notice and Stock Option Agreement, dated (the “Option Agreement”). Capitalized terms used herein without definition shall have the meanings given in the Option Agreement.

Exercise of Option. I hereby elect to exercise the Option to purchase the following number of Shares, all of with are Vested Shares in accordance with the Notice and/or Option Agreement: