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	60,975	—	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	7,424	—	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	263,870	—	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	26,416	—	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	961	—	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	31,884	—	I

Explanation of responses

F1This amendment reduces the number of shares issuable on conversion of the Notes as described in footnotes 2, 4, 6, 8, 10, 12 below and the Underlying Securities in Column 7 due to acquisition of beneficial ownership of shares as reported on a Form 4 filed the same date as this Amendment on March 31, 2016.
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 30,070,750 shares outstanding on March 23, 2016, all of the Notes together when issued were convertible into a maximum of 391,530 shares. The Reporting Owner's Note when issued was convertible into a maximum of 961 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 30,070,750 shares outstanding on March 23, 2016, all of the Notes together when issued were convertible into a maximum of 391,530 shares. The Reporting Owner's Note when issued was convertible into a maximum of 31,884 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 30,070,750 shares outstanding on March 23, 2016, all of the Notes together when issued were convertible into a maximum of 391,530 shares. The Reporting Owner's Note when issued was convertible into a maximum of 60,975 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 30,070,750 shares outstanding on March 23, 2016, all of the Notes together when issued were convertible into a maximum of 391,530 shares. The Reporting Owner's Note when issued was convertible into a maximum of 7,424 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 30,070,750 shares outstanding on March 23, 2016, all of the Notes together when issued were convertible into a maximum of 391,530 shares. The Reporting Owner's Note when issued was convertible into a maximum of 263,870 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 30,070,750 shares outstanding on March 23, 2016, all of the Notes together when issued were convertible into a maximum of 391,530 shares. The Reporting Owner's Note when issued was convertible into a maximum of 26,416 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.