X0206 3 2020-10-29 0 0001604477 SQZ Biotechnologies Co SQZ 0001262409 BERNSTEIN HOWARD PHD MD 200 ARSENAL YARDS BLVD, SUITE 210 WATERTOWN MA 02472 0 1 0 0 Chief Scientific Officer Common Stock 59470 D Stock Option 1.81 2026-10-18 Common Stock 44226 D Stock Option 2.02 2028-03-04 Common Stock 13174 D Stock Option 4.59 2028-11-06 Common Stock 94006 D Stock Option 4.59 2029-02-18 Common Stock 47385 D Stock Option 7.92 2030-02-26 Common Stock 26325 D The option vests and becomes exercisable as to 25% of the underlying securities on October 11, 2017 and in 36 equal monthly installments thereafter. The option vests and becomes exercisable as to 25% of the underlying securities on January 23, 2019 and in 36 equal monthly installments thereafter. The option vests and becomes exercisable as to 25% of the underlying securities on October 29, 2019 and in 36 equal monthly installments thereafter. The option vests and becomes exercisable as to 25% of the underlying securities on February 1, 2020 and in 36 equal monthly installments thereafter. The option vests and becomes exercisable as to 25% of the underlying securities on February 18, 2021 and in 36 equal monthly installments thereafter. Exhibit 24 - Power of Attorney. /s/ Lawrence Knopf, Attorney-in-Fact for Howard Bernstein 2020-10-29