X0306 4 2016-02-09 0 0001604464 Atara Biotherapeutics, Inc. ATRA 0001612096 Ciechanover Isaac E. 701 GATEWAY BOULEVARD SUITE 200 SOUTH SAN FRANCISCO CA 94080 1 1 0 0 Chief Executive Officer Common Stock 2016-02-09 4 A 0 163973 0.00 A 211413 I See Footnote Common Stock 379211 I See Footnote Common Stock 450824 I See Footnote Common Stock 180000 I See Footnote These restricted stock units vest in four equal annual installments on each of the first, second, third and fourth anniversaries of the grant date, subject to the reporting person's continuous service. Shares are held by the Isaac E. Ciechanover and Allison M. Ciechanover Family Trust dated 8/8/08, of which the Reporting Person is a trustee. Sheld are held by the Ciechanover Family GRAT, of which the Reporting Person is a trustee. Sheld are held by the The Ciechanover 2015 GRAT, of which the Reporting Person is a trustee. /s/ Tina Gullotta, Attorney-in-Fact for Isaac E. Ciechanover 2016-02-11