EXHIBIT A
Joint Filing Statement
We, the undersigned, hereby express our agreement that the attached Schedule 13D is filed on behalf of each of us.
| THE COLUMN GROUP, LP | THE COLUMN GROUP GP, LP | |||||||
| By: | The Column Group GP, LP | |||||||
| By: | /s/ Peter Svennilson | By: | /s/ Peter Svennilson | |||||
| Name: | Peter Svennilson | Name: | Peter Svennilson | |||||
| Title: | Managing Partner | Title: | Managing Partner | |||||
| By: | /s/ Peter Svennilson | |||||||
| Peter Svennilson | ||||||||
| By: | /s/ David V. Goeddel | |||||||
| David V. Goeddel | ||||||||
