X0407 4 2023-04-24 0 0001680048 MUSTANG BIO, INC. MBIO 0001709485 Litchman Manuel MD 377 PLANTATION STREET WORCESTER MA 01605 1 1 0 0 President and CEO 0 COMMON STOCK, PAR VALUE $0.0001 2023-04-24 4 A 0 5000 0.000 A 111079 D Represents an award of 5,000 restricted stock units that will vest in four annual installments after the grant date, vesting in full on April 24, 2027. Effective April 3, 2023, the Issuer effected a fifteen-for-one reverse stock split of its common stock (the "Reverse Stock Split"). The amount of common stock reflected on this Form 4 has been adjusted to reflect the Reverse Stock Split. Includes restricted share units, which vest over various time periods. /s/ Matthew Wein, Attorney-in-Fact 2023-07-07