Purity >98%. Ac-DEVD-CHO is a potent inhibitor of the Group II caspases, caspase-3 and caspase-7 (Ki s = 0.23 and 1.6 nM, respectively). Notably, it also inhibits other caspases (Ki s = 18, 1710, 132, 205, 31, 0.92, 60, and 12 nM for caspases-1, -2, -4, -5, -6, -8, -9, and -10, respectively). Caspase inhibitors in the aldehyde form, like this compound, are typically reversible, whereas methyl ketone forms, like Ac-DEVD-CMK , are irreversible. Caspase inhibitors interfere with the initiation of apoptosis and have numerous possible clinical applications.