X0306 4 2015-05-14 0 0001604464 Atara Biotherapeutics, Inc. ATRA 0001547840 Kleiner Perkins Caufield & Byers XV, LLC 2750 SAND HILL ROAD MENLO PARK CA 94025 0 0 1 0 0001547838 KPCB XV Associates, LLC 2750 SAND HILL ROAD MENLO PARK CA 94025 0 0 1 0 0001547839 KPCB XV Founders Fund, LLC 2750 SAND HILL ROAD MENLO PARK CA 94025 0 0 1 0 Common Stock 2015-05-14 4 J 0 194200 0.00 D 2404828 I See Footnote Common Stock 2015-05-14 4 J 0 5800 0.00 D 71822 I See Footnote Pro rata distribution to the members of Kleiner Perkins Caufield & Byers XV, LLC ("KPCB XV") pursuant to the terms of its operating agreement. Ending balance reflects correction of 1 share reallocation from KPCB XV to KPCB XV Founders Fund, LLC ("KPCB XV FF"). Allocations in the original Form 3 reflected 2,599,029 shares held by KPCB XV and 77,621 shares held by KPCB XV FF. The shares are directly held by KPCB XV. All shares are held for convenience in the name of "KPCB Holdings, Inc., as nominee". The managing member of KPCB XV is KPCB XV Associates, LLC ("XV Associates"). The voting and dispositive control over the shares is shared by individual managing members of XV Associates, none of whom has veto power. Pro rata distribution to the members of KPCB XV FF pursuant to the terms of its operating agreement. The shares are directly held by KPCB XV FF. All shares are held for convenience in the name of "KPCB Holdings, Inc., as nominee". The managing member of KPCB XV FF is XV Associates. The voting and dispositive control over the shares is shared by individual managing members of XV Associates, none of whom has veto power. /s/ Paul Vronsky, General Counsel 2015-05-18 /s/Paul Vronsky, Attorney-in-Fact 2015-05-18 /s/Paul Vronsky, Attorney-in-Fact 2015-05-18