X0306 4 2018-05-16 0 0001497253 ORGANOVO HOLDINGS, INC. ONVO 0001536585 Presnell Sharon Collins 6275 NANCY RIDGE DRIVE, SUITE 110 SAN DIEGO CA 92121 0 1 0 0 Chief Scientific Officer Common Stock 2018-05-16 4 F 0 8325 1.6621 D 269468 D Represents the mandatory sale of shares to satisfy the Reporting Person's tax withholding obligations, in connection with the partial vesting and settlement of restricted stock units granted in July 2016 and June 2017, pursuant to the Reporting Person's agreement with the Issuer. This number does not include 1,282,192 shares of common stock underlying outstanding options held by Dr. Presnell; post-transaction Dr. Presnell beneficially owns or has a right to acquire 1,551,660 shares of common stock. /s/ Sharon Presnell 2018-05-17