X0206 3 2020-10-29 0 0001604477 SQZ Biotechnologies Co SQZ 0001829257 Jensen Klavs F. 200 ARSENAL YARDS BLVD, SUITE 210 WATERTOWN MA 02472 1 0 0 0 Common Stock 324320 D Series Seed Convertible Preferred Stock Common Stock 7388 D Series B Convertible Preferred Stock Common Stock 7274 D Stock Option 2.02 2028-03-04 Common Stock 824 D Stock Option 4.59 2029-02-18 Common Stock 1536 D The Issuer's preferred stock is convertible into common stock on a 1.053 for 1 basis at the holder's election and will automatically convert upon closing of the initial public offering of the Issuer's common stock. The shares have no expiration date. This option was originally granted for 2,632 shares underlying the option grant. The option vested and became exercisable as to 25% of the original grant amount on January 23, 2019 and in 36 equal monthly installments thereafter. This option was originally granted for 2,632 shares underlying the option grant. The option vested and became exercisable as to 25% of the underlying securities on February 1, 2020 and in 36 equal monthly installments thereafter. Exhibit 24 - Power of Attorney. /s/ Lawrence Knopf, Attorney-in-Fact for Klavs F. Jensen 2020-10-29