X0206 3 2020-10-29 0 0001604477 SQZ Biotechnologies Co SQZ 0001021944 Temasek Holdings (Private) Ltd 60B ORCHARD ROAD, #06-18 TOWER 2 THEATRIUM@ORCHARD SINGAPORE U0 233891 SINGAPORE 0 0 1 0 Series D Preferred Stock Common Stock 1888924 I See note The Series D Preferred Stock is convertible into Common Stock on a 1:1 basis at any time upon the holder's election and has no expiration date. All shares of Series D Preferred Stock shall be automatically converted into shares of Common Stock upon the closing of the Issuer's initial public offering. The shares are held of record by Elbrus Investments Pte. Ltd. ("Elbrus"). Elbrus is a direct wholly owned subsidiary of Temasek Life Sciences Private Limited, which in turn is a direct wholly owned subsidiary of Fullerton Management Pte Ltd, which in turn is a direct wholly owned subsidiary of Temasek Holdings (Private) Limited ("Temasek"). Therefore, Temasek may be deemed to beneficially own the shares held of record by Elbrus. TEMASEK HOLDINGS (PRIVATE) LIMITED, By: /s/ Gregory Tan, in his capacity as Authorized Signatory 2020-10-29