X0306 4 2020-05-06 0 0001770787 10x Genomics, Inc. TXG 0001581219 Foresite Capital Management I, LLC 600 MONTGOMERY STREET, SUITE 4500 SAN FRANCISCO CA 94111 0 0 1 0 0001562157 Foresite Capital Fund I, L.P. 600 MONTGOMERY STREET, SUITE 4500 SAN FRANCISCO CA 94111 0 0 1 0 0001594912 Foresite Capital Management II, LLC 600 MONTGOMERY STREET, SUITE 4500 SAN FRANCISCO CA 94111 0 0 1 0 0001594914 Foresite Capital Fund II, L.P. 600 MONTGOMERY STREET, SUITE 4500 SAN FRANCISCO CA 94111 0 0 1 0 0001581754 Tananbaum James B. 600 MONTGOMERY STREET, SUITE 4500 SAN FRANCISCO CA 94111 0 0 1 0 Class A Common Stock 2020-05-06 4 C 0 500000 A 2369802 I See footnote Class A Common Stock 2020-05-06 4 C 0 1500000 A 3000000 I See footnote Class A Common Stock 327383 I See footnote Class B Common Stock 2020-05-06 4 C 0 500000 D Class A Common Stock 500000 1930198 I See Footnote Class B Common Stock 2020-05-06 4 C 0 1500000 D Class A Common Stock 1500000 3153528 I See Footnote Each share of Class B Common Stock is convertible, for no additional consideration, into one (1) share of Class A Common Stock at any time at the holder's election. The shares are owned directly by Foresite Capital Fund I, L.P. ("FCF I"). Foresite Capital Management I, LLC ("FCM I"), the general partner of FCF I, may be deemed to have sole voting and dispositive power over these shares. Mr. Tananbaum, in his capacity as managing member of FCM I, may be deemed to have sole voting and dispositive power over these shares. Each Reporting Person disclaims the existence of a "group." Each of FCM I and its members and Mr. Tananbaum disclaims beneficial ownership of any of these shares except to the extent of any pecuniary interest therein, and the filing of this report is not an admission that FCM I and its members or Mr. Tananbaum is the beneficial owner of these shares for purposes of Section 16 or any other purpose. The shares are owned directly by Foresite Capital Fund II, L.P. ("FCF II"). Foresite Capital Management II, LLC ("FCM II"), the general partner of FCF II, may be deemed to have sole voting and dispositive power over these shares. Mr. Tananbaum, in his capacity as managing member of FCM II, may be deemed to have sole voting and dispositive power over these shares. Each Reporting Person disclaims the existence of a "group." Each of FCM II and its members and Mr. Tananbaum disclaims beneficial ownership of any of these shares except to the extent of any pecuniary interest therein, and the filing of this report is not an admission that FCM II and its members or Mr. Tananbaum is the beneficial owner of these shares for purposes of Section 16 or any other purpose. The shares are owned by James B. Tananbaum and Dana Shonfeld Tananbaum Family Trust ("Trust") of which Mr. Tananbaum is the trustee. Mr. Tananbaum disclaims beneficial ownership of any of these shares except to the extent of any pecuniary interest therein. The Class B Common Stock has no expiration date. FORESITE CAPITAL MANAGEMENT I, LLC, By: /s/ James B. Tananbaum, Managing Member 2020-05-07 FORESITE CAPITAL FUND I, L.P., By: Foresite Capital Management I, LLC, Its: General Partner, By: /s/ James B. Tananbaum, Managing Member 2020-05-07 FORESITE CAPITAL MANAGEMENT II, LLC, By: /s/ James B. Tananbaum, Managing Member 2020-05-07 FORESITE CAPITAL FUND II, L.P., By: Foresite Capital Management II, LLC, Its: General Partner, By: /s/ James B. Tananbaum, Managing Member 2020-05-07 By: /s/ James B. Tananbaum 2020-05-07