X0306 4 2018-11-07 0 0001604464 Atara Biotherapeutics, Inc. ATRA 0001216955 MARCUS JOEL S C/O ALEXANDRIA REAL ESTATE EQUITIES, INC 385 EAST COLORADO BOULEVARD, SUITE 299 PASADENA CA 91101 1 0 0 0 Common Stock 2018-11-07 4 S 0 10000 36.35 D 7590 D Common Stock 4000 I Held by the Joel S. Marcus and Barbara A. Marcus Family Trust Common Stock 908355 I See footnote The price in Column 4 is a weighted average sale price. The prices actually received ranged from $36.201 to $36.641. The reporting person will provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Consists of shares of common stock held by Alexandria Equities, LLC. Mr. Marcus is the Chairman, CEO and Founder of Alexandria Real Estate Equities, Inc., which is the managing member of Alexandria Equities, LLC, which has full voting and investment power with respect to the shares owned by Alexandria Equities, LLC. As an officer of Alexandria Real Estate Equities, Inc., Mr. Marcus may be deemed to have voting and investment power with respect to the shares owned by Alexandria Equities, LLC. Mr. Marcus disclaims beneficial ownership of the shares held by Alexandria Equities, LLC, except to the extent of his underlying pecuniary interest therein. /s/ David Tucker, Attorney-in-Fact 2018-11-08