X0609 4/A 2026-06-12 2026-06-16 0001661998 Q32 Bio Inc. QTTB 0001586226 TZIANABOS ARTHUR false Q32 BIO INC. 830 WINTER STREET WALTHAM MA 02451 true false false false false Stock Option (Right to Buy) 12.64 2026-06-12 4 A false 10826 0 A 2036-06-11 Common Stock 10826 10826 D This Form 4 amendment is being filed solely to amend the Form 4 filed on June 16, 2026 to correct the number of options awarded to the Reporting Person on June 12, 2026. The shares underlying this option shall vest and become exercisable in full upon the earlier of (i) June 12, 2027 or (ii) the date of the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continued service on such vesting date. /s/ Eric Bell, Attorney-in-Fact 2026-07-21