Thistle Mary 4/A

What Happened
Mary Thistle, a director of Q32 Bio, was granted a derivative award (an option) covering 10,826 shares with a reported acquisition price of $0.00 on June 12, 2026. This Form 4 is an amendment filed July 21, 2026 to correct the number of options reported in the original Form 4 filed June 16, 2026.

Key Details

• Transaction date: June 12, 2026; Form 4 amendment filed July 21, 2026.
• Transaction type: Grant / award of a derivative security (code A on the Form 4). Reported acquisition price: $0.00.
• Shares/options: 10,826 underlying shares granted.
• Vesting: The shares underlying the option vest and become exercisable in full upon the earlier of (i) June 12, 2027 or (ii) the issuer’s next annual meeting of stockholders, subject to continued service. (Footnote F2)
• Amendment note: Form 4 amendment was filed solely to correct the number of options awarded (Footnote F1).
• Post-transaction total holdings: Not provided in the information supplied.

Context
This was an equity award (derivative grant), not an open-market purchase or sale; there is no indication the options were exercised or any shares sold. Equity awards to directors are common as compensation and do not by themselves indicate a buying/selling signal. The amendment corrects reporting details; the original Form 4 was filed June 16, 2026 and this filing updates the award quantity.