Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Class B Common Stock^F1	Nov 12, 2015	P	22,061	$3.85	A	1,028,061	I	By Funds
Class B Common Stock^F2	Nov 13, 2015	P	56,242	$3.85	A	1,084,303	I	By Funds
Class B Common Stock^F3	Nov 16, 2015	P	51,127	$3.84	A	1,135,430	I	By Funds

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1Venrock Associates V, L.P. ("VA5") holds an aggregate of 927,654 shares, Venrock Partners V, L.P. ("VP5") holds an aggregate of 78,587 shares and Venrock Entrepreneurs Fund V, L.P. ("VEF5") holds an aggregate of 21,820 shares. Venrock Management V, LLC, VEF Management V, LLC and Venrock Partners Management V, LLC (collectively, the "Venrock GP Entities") are the sole general partners of VA5, VEF5 and VP5 (collectively, the "Funds"), respectively, and have voting and investment power over the shares held by the Funds. Each of the Venrock GP Entities disclaims beneficial ownership of the shares held by the Funds, except to the extent of their respective indirect pecuniary interests therein.
F2VA5 holds an aggregate of 978,403 shares, VP5 holds an aggregate of 82,886 shares and VEF5 holds an aggregate of 23,014 shares. The Venrock GP Entities are the sole general partners of the Funds, and have voting and investment power over the shares held by the Funds. Each of the Venrock GP Entities disclaims beneficial ownership of the shares held by the Funds, except to the extent of their respective indirect pecuniary interests therein.
F3VA5 holds an aggregate of 1,024,499 shares, VP5 holds an aggregate of 86,860 shares and VEF5 holds an aggregate of 24,071 shares. The Venrock GP Entities are the sole general partners of the Funds, and have voting and investment power over the shares held by the Funds. Each of the Venrock GP Entities disclaims beneficial ownership of the shares held by the Funds, except to the extent of their respective indirect pecuniary interests therein.