Annual Retainers. Each Non-Employee Director shall receive an annual retainer of ​ for service on the Board. Each Non-Employee Director shall also receive ​ annually in addition to the annual retainer for serving as a Board Chair for one of the three (3) established Board Committees: Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee.

Additional Annual Retainers. In addition, each Non-Employee Director shall receive the following additional annual retainers, as applicable:

For service as member of the nominating and corporate governance committee other than as its Chair: an annual cash retainer of ​ (in addition to any annual cash retainers otherwise paid).

For service as member of the science, technology and clinical affairs committee other than as its Chair: an annual cash retainer of ​ (in addition to any annual cash retainers otherwise paid).

Eligible Director compensation covered by this Plan includes annual retainers (including committee retainers) generally payable on or shortly after January 1 of each calendar year (hereinafter “Eligible Fees”). The Plan permits Eligible Directors to elect to receive this compensation in one or more of the following methods:

The annual cash retainers above will be payable in equal quarterly installments in arrears on the last day of each fiscal quarter (each such date, a “Retainer Accrual Date”) in which the service occurred, prorated for any partial quarter of service (based on the number of days served in the applicable position divided by the total number of days in the quarter). All annual cash retainers will be vested upon payment.

Under the policy, each of our non-employee, independent directors is eligible to receive annual retainers for board and committee service as follows:

In addition, a Non-Employee Director shall be eligible to receive the following additional annual cash retainers for service in the following roles:

Annual Cash Retainers for Service as Outside Director. Each Outside Director will be paid a cash retainer of ​ per year. There are no per‑meeting attendance fees for attending Board meetings or meetings of any committee of the Board.

Payment of Retainers. For the avoidance of doubt, the Annual Retainers in the table above are additive and a Non-Employee Director shall be eligible to earn an Annual Retainer for each position in which he or she serves. The Annual Retainers shall be earned on a quarterly basis based on a calendar quarter and, except as otherwise provided in [Section I(B)], shall be paid in cash by the Company in arrears not later than the fifteenth day following the end of each calendar quarter. In the event a Non-Employee Director does not serve as a Non-Employee Director, or in the applicable position, for an entire calendar quarter, the Annual Retainer paid to such Non-Employee Director pursuant to this [Section I(A)] shall be prorated for the portion of such calendar quarter actually served as a Non-Employee Director, or in such position, as applicable.

Annual Awards. Each Non-Employee Director who # serves on the Board as of the date of any annual meeting of the Company’s stockholders (an “Annual Meeting”) and # will continue to serve as a Non-Employee Director immediately following such Annual Meeting shall be automatically granted, on the date of such Annual Meeting, an award of restricted stock units that have an aggregate fair value on the date of such Annual Meeting of ​ (as determined in accordance with ASC 718 and with the number of shares of common stock underlying such award subject to adjustment as provided in the Equity Plan). The awards described in this [Section 2(a)] shall be referred to as the “Annual Awards.” For the avoidance of doubt, if the Company’s Annual Meeting does not occur by June 30 of each calendar year, each Non-Employee Director shall be automatically granted an Annual Award on June 30.

Annual RSUs. Each award of Annual RSUs shall vest on the earlier of the first anniversary of the date of grant or the day immediately prior to the date of the next annual meeting of the Company’s stockholders occurring after the date of grant, in either case, subject to the Non-Employee Director continuing in service as a Non-Employee Director through such vesting date.