Transaction Details

Footnotes

The securities are directly held by The Column Group III, LP ("TCG III LP). The Column Group III GP, LP ("TCG III GP") is the general partner of TCG III LP and may be deemed to have voting, investment and dispositive power with respect to these securities. The managing partners of TCG III GP are David Goeddel, Peter Svennilson and The Reporting Person, a member of the Issuer's board of directors (collectively, the "Managing Partners"). The Managing Partners may be deemed to share voting and investment power with respect to such securities. TCG III GP and each of the Managing Partners disclaim beneficial ownership of these securities, except to the extent of their respective pecuniary interest in such securities. | The securities are directly held by The Column Group III-A, LP ("TCG III-A LP). TCG III GP is the general partner of TCG III-A LP and may be deemed to have voting, investment and dispositive power with respect to these securities. The managing partners of TCG III GP are the Managing Partners. The Managing Partners may be deemed to share voting and investment power with respect to such securities. TCG III GP and each of the Managing Partners disclaim beneficial ownership of these securities, except to the extent of their respective pecuniary interest in such securities. | The securities are directly held by The Column Group Opportunity III, LP ("TCG Opportunity III LP"). The Column Group Opportunity III GP, LP ("TCG Opportunity III GP LP") is the general partner of TCG Opportunity III LP and may be deemed to have voting, investment and dispositive power with respect to these securities. TCG Opportunity III GP, LLC ("TCG Opportunity III GP LLC") is the general partner of TCG Opportunity III GP LP and the ultimate general partner of TCG Opportunity III LP and may be deemed to have voting, investment and dispositive power with respect to these securities. The managing members of TCG Opportunity III GP LLC are the Managing Partners. TCG Opportunity III GP LP, TCG Opportunity III GP LLC and each of the Managing Partners disclaim beneficial ownership of these securities, except to the extent of their respective pecuniary interest in such securities.