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. Effective as of today, ,Pursuant to the undersignedStock Option Grant Notice (the “Optionee”“Grant Notice”) hereby elects to exercise Optionee’s option to purchase shares of the Commonwhich this Stock Option Agreement (the “Shares”“Agreement”) ofis attached, Gritstone Oncology, Inc., a Delaware corporation (the “Company”), has granted to Optionee (as set forth in the Grant Notice) an option to purchase the number of Shares (as defined in the Grant Notice) under and pursuant to the Gritstone Oncology, Inc. 2015 Equity Incentive Plan, as amended from time to timePlan (the “Plan”), and indicated in the Stock Option Grant Notice and Stock Option Agreement, dated (the “Option Agreement”). Capitalized terms used herein without definition shall haveat the meanings givenexercise price per share set forth in the Option Agreement.Grant Notice (the “Exercise Price”).

Exercise of Option. Effective as of today, , the undersigned (the “Optionee”) hereby electsPursuant 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.its 2015 Equity Incentive Plan, as amended from time to time (the “Plan”), Gritstone Oncology, Inc., a Delaware corporation (the “Company”), hereby grants to the individual listed below (the “Optionee”), an option to purchase the number of shares of the Company’s Common Stock set forth below (the “Option”), subject to the terms and conditions set forth herein, in the Plan, and in the certain Stock Option Agreement attached hereto as [Exhibit A] (the “Option Agreement”), each of which is incorporated herein by reference. Unless otherwise defined herein, the terms defined in the Plan shall have the same defined meanings in this Stock Option Grant Notice and Stock Option Agreement, dated (the “Option Agreement”“Grant Notice”). Capitalized terms used herein without definition shall have the meanings given in and the Option Agreement.

ExerciseIn connection with the purchase of Option. Effective as of today, , the undersigned (the “Optionee”) hereby elects to exercise Optionee’s option to purchaseabove-listed shares of the Common Stock (the “Shares”“Securities”) of Gritstone Oncology, Inc., a Delaware corporation (the “Company”), under and pursuantthe undersigned (the “Optionee”) represents to the Gritstone Oncology, Inc. 2015 Equity Incentive Plan, as amended from time to time (the “Plan”), andCompany 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.following: