EXHIBIT 4
Joint Filing Statement
We, the undersigned, hereby express our agreement that the attached Schedule 13D is filed on behalf of each of us.
Date: December 10, 2012
| By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for Harvey B. Cash | |
By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for Christopher B. Ehrlich | |
By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for Philip T. Gianos | |
By: | /s/ W. Stephen Holmes W. Stephen Holmes | |
By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for Gilbert H. Kliman | |
By: | /s/ Karen A. Wilson | |
Karen A. Wilson as Attorney-in-fact for Arnold L. Oronsky | ||
By: | /s/ Karen A. Wilson | |
Karen A. Wilson as Attorney-in-fact for Thomas L. Rosch | ||
By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for W. Scott Hedrick | |
By: | /s/ Karen A. Wilson | |
Karen A. Wilson as Attorney-in-fact for Nina S. Kjellson | ||
By: | /s/ Karen A. Wilson | |
Karen A. Wilson as Attorney-in-fact for Douglas A. Pepper | ||
| INTERWEST PARTNERS VIII, L.P. | ||
By: InterWest Management Partners VIII, L.L.C. Its: General Partner | ||
| By: | /s/ W. Stephen Holmes W. Stephen Holmes Managing Director | |
| INTERWEST INVESTORS VIII, L.P. | ||
By: InterWest Management Partners VIII, L.L.C. Its: General Partner | ||
| By: | /s/ W. Stephen Holmes W. Stephen Holmes Managing Director | |
| INTERWEST INVESTORS Q VIII, L.P. | ||
By: InterWest Management Partners VIII, L.L.C. Its: General Partner | ||
| By: | /s/ W. Stephen Holmes W. Stephen Holmes Managing Director | |
| INTERWEST MANAGEMENT PARTNERS VIII, L.L.C. | ||
| By: | /s/ W. Stephen Holmes W. Stephen Holmes Managing Director | |
| INTERWEST PARTNERS X, L.P. | ||
By: InterWest Management Partners X, L.L.C. Its: General Partner | ||
| By: | /s/ W. Stephen Holmes W. Stephen Holmes Managing Director | |
| By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for Bruce Cleveland | |
| By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for Khaled A. Nasr | |
| By: | /s/ Karen A. Wilson Karen A. Wilson as Attorney-in-fact for Keval Desai | |
| INTERWEST MANAGEMENT PARTNERS X, L.L.C. | ||
| By: | /s/ W. Stephen Holmes W. Stephen Holmes Managing Director | |
