Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
4.00% Convertible Secured Subordinated Notes^F1,F2,F3	$5.00	Dec 17, 2015	P	—	A	Dec 17, 2015	Apr 15, 2018	Common Stock	61,320	—	I
4.00% Convertible Secured Subordinated Notes^F1,F4,F5	$5.00	Dec 17, 2015	P	—	A	Dec 17, 2015	Apr 15, 2018	Common Stock	7,466	—	I
4.00% Convertible Secured Subordinated Notes^F1,F6,F7	$5.00	Dec 17, 2015	P	—	A	Dec 17, 2015	Apr 15, 2018	Common Stock	265,366	—	I
4.00% Convertible Secured Subordinated Notes^F1,F8,F9	$5.00	Dec 17, 2015	P	—	A	Dec 17, 2015	Apr 15, 2018	Common Stock	26,566	—	I
4.00% Convertible Secured Subordinated Notes^F1,F10,F11	$5.00	Dec 17, 2015	P	—	A	Dec 17, 2015	Apr 15, 2018	Common Stock	967	—	I
4.00% Convertible Secured Subordinated Notes^F1,F12,F13	$5.00	Dec 17, 2015	P	—	A	Dec 17, 2015	Apr 15, 2018	Common Stock	32,064	—	I

Explanation of responses

F1This amendment reduces the number of shares issuable in footnotes 2, 4, 6, 8, 10, 12 below and the Underlying Securities in Column 7 as a result of an option to purchase Common Stock granted in 2015 which on March 1, 2016 became exercisable within 60 days.
F10The number of shares issuable on conversion of all Notes is subject to a limit which varies over time depending on the Issuer's then-outstanding shares of Common Stock and any other acquisitions of beneficial ownership by a Reporting Owner during the preceding 12 months. Based on 29,421,308 shares outstanding on November 6, 2015, all of the Notes together when issued were convertible into a maximum of 393,749 shares. The Reporting Owner's Note when issued was convertible into a maximum of 967 shares.
F11These securities are directly held by VantagePoint Venture Partners IV Principals Fund, L.P. VantagePoint Venture Associates IV, L.L.C. is the general partner of VantagePoint Venture Partners IV Principals Fund, L.P. VantagePoint Venture Associates IV, L.L.C. disclaims beneficial ownership of such securities except to the extent of its pecuniary interest in such securities. Alan E. Salzman, a managing member of VantagePoint Venture Associates IV, L.L.C., disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interests therein.
F12The number of shares issuable on conversion of all Notes is subject to a limit which varies over time depending on the Issuer's then-outstanding shares of Common Stock and any other acquisitions of beneficial ownership by a Reporting Owner during the preceding 12 months. Based on 29,421,308 shares outstanding on November 6, 2015, all of the Notes together when issued were convertible into a maximum of 393,749 shares. The Reporting Owner's Note when issued was convertible into a maximum of 32,064 shares.
F13These securities are directly held by VantagePoint Venture Partners 2006 (Q), L.P. VantagePoint Venture Associates 2006, L.L.C. is the general partner of VantagePoint Venture Partners 2006 (Q), L.P. VantagePoint Venture Associates 2006, L.L.C. disclaims beneficial ownership of such securities except to the extent of its pecuniary interest in such securities. Alan E. Salzman, a managing member of VantagePoint Venture Associates 2006, L.L.C., disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interests therein.
F2The number of shares issuable on conversion of all Notes is subject to a limit which varies over time depending on the Issuer's then-outstanding shares of Common Stock and any other acquisitions of beneficial ownership by a Reporting Owner during the preceding 12 months. Based on 29,421,308 shares outstanding on November 6, 2015, all of the Notes together when issued were convertible into a maximum of 393,749 shares. The Reporting Owner's Note when issued was convertible into a maximum of 61,320 shares.
F3These securities are directly held by VantagePoint Venture Partners III (Q), L.P. VantagePoint Venture Associates III, L.L.C. is the general partner of VantagePoint Venture Partners III (Q), L.P. VantagePoint Venture Associates III, L.L.C. disclaims beneficial ownership of such securities except to the extent of its pecuniary interest in such securities. Alan E. Salzman, a managing member of VantagePoint Venture Associates III, L.L.C., disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interests therein.
F4The number of shares issuable on conversion of all Notes is subject to a limit which varies over time depending on the Issuer's then-outstanding shares of Common Stock and any other acquisitions of beneficial ownership by a Reporting Owner during the preceding 12 months. Based on 29,421,308 shares outstanding on November 6, 2015, all of the Notes together when issued were convertible into a maximum of 393,749 shares. The Reporting Owner's Note when issued was convertible into a maximum of 7,466 shares.
F5These securities are directly held by VantagePoint Venture Partners III, L.P. VantagePoint Venture Associates III, L.L.C. is the general partner of VantagePoint Venture Partners III, L.P. VantagePoint Venture Associates III, L.L.C. disclaims beneficial ownership of such securities except to the extent of its pecuniary interest in such securities. Alan E. Salzman, a managing member of VantagePoint Venture Associates III, L.L.C., disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interests therein.
F6The number of shares issuable on conversion of all Notes is subject to a limit which varies over time depending on the Issuer's then-outstanding shares of Common Stock and any other acquisitions of beneficial ownership by a Reporting Owner during the preceding 12 months. Based on 29,421,308 shares outstanding on November 6, 2015, all of the Notes together when issued were convertible into a maximum of 393,749 shares. The Reporting Owner's Note when issued was convertible into a maximum of 265,366 shares.
F7These securities are directly held by VantagePoint Venture Partners IV (Q), L.P. VantagePoint Venture Associates IV, L.L.C. is the general partner of VantagePoint Venture Partners IV (Q), L.P. VantagePoint Venture Associates IV, L.L.C. disclaims beneficial ownership of such securities except to the extent of its pecuniary interest in such securities. Alan E. Salzman, a managing member of VantagePoint Venture Associates IV, L.L.C., disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interests therein.
F8The number of shares issuable on conversion of all Notes is subject to a limit which varies over time depending on the Issuer's then-outstanding shares of Common Stock and any other acquisitions of beneficial ownership by a Reporting Owner during the preceding 12 months. Based on 29,421,308 shares outstanding on November 6, 2015, all of the Notes together when issued were convertible into a maximum of 393,749 shares. The Reporting Owner's Note when issued was convertible into a maximum of 26,566 shares.
F9These securities are directly held by VantagePoint Venture Partners IV, L.P. VantagePoint Venture Associates IV, L.L.C. is the general partner of VantagePoint Venture Partners IV, L.P. VantagePoint Venture Associates IV, L.L.C. disclaims beneficial ownership of such securities except to the extent of its pecuniary interest in such securities. Alan E. Salzman, a managing member of VantagePoint Venture Associates IV, L.L.C., disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interests therein.