Transaction Details

Footnotes

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.60 to $0.63, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. | The securities are directly held by The Column Group III, LP ("TCG III 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 Peter Svennilson and Tim Kutzkey (together, the "Managing Partners"). The Managing Partners may be deemed to share voting, investment and dispositive power with respect to such shares. TCG III GP and each of the Managing Partners disclaim beneficial ownership of these shares, except to the extent of their respective pecuniary interest in such shares. | 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, investment and dispositive power with respect to such shares. TCG III GP and each of the Managing Partners disclaim beneficial ownership of these shares, except to the extent of their respective pecuniary interest in such shares. | The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.573 to $0.6225, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. | The securities are directly held by 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. The Managing Partners may be deemed to share voting, investment and dispositive power with respect to such securities. 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.