Sigilon Therapeutics, Inc. Non-Employee Director Compensation Policy

Type of
Compensation

Amount and
Form of Payment

Annual cash fee

$35,000 ($65,000 for the chairman of the Board of Directors (the “Board”))

Additional annual cash fee for members of the Audit Committee

$7,500 ($15,000 for the Audit Committee chairman)

Additional annual cash fee for members of the Compensation Committee

$5,000 ($10,000 for the Compensation Committee chairman)

Additional annual cash fee for members of the Nominating and Corporate Governance Committee

$4,000 ($8,000 for the Nominating and Corporate Governance Committee chairman)

Equity compensation

Each Non-Employee Director who is first elected or appointed to the Board following the IPO shall, upon his or her initial election or appointment to the Board, be granted an option to purchase 40,000 shares of the Company’s common stock (the “Initial Option”), such option to vest as to one-third of the shares subject to the option on each of the first, second and third anniversaries of the date of grant, subject to the Non-Employee Director’s continued service to the Board through each applicable vesting date. Notwithstanding the foregoing, in no event will the Initial Option have a grant date fair value, determined in accordance with FASB ASC Topic 718 (or any successor provision) (“ASC Topic 718”), that exceeds $600,000.

On the date of the first meeting of the Board following each annual meeting of stockholders of the Company, each Non-Employee Director who has then served as a member of the Board for at least a six (6)-month period prior to such meeting will be granted an option to purchase 20,000 shares of the Company’s common stock (the “Annual Option”), such option to vest in full on the first anniversary of the date of grant, subject to the Non-

Employee Director’s continued service to the Board through the applicable vesting date. Notwithstanding the foregoing, in no event will the Annual Option have a grant date fair value, determined in accordance with FASB ASC Topic 718 (or any successor provision) (“ASC Topic 718”), that exceeds $300,000.

Each option granted to any Non-Employee Director will have a per-share exercise price equal to the fair market value of a share of the Company’s common stock on the date of grant, have a term of no more than ten (10) years and will be subject to the terms and conditions of the Company’s 2020 Equity Incentive Plan (or any successor plan). Upon a Change in Control (as defined in the Company’s 2020 Equity Incentive Plan (or as such term or similar term is defined in any successor plan)), each Initial Option and each Annual Option that is then outstanding will vest in full, subject to the Non-Employee Director’s continued service to the Board through such Change in Control.