SIRT-IN-4 is an inhibitor of the NAD+-dependent lysine deacetylase Sirtuin2 ( Sirt2 )( IC 50 =0.35 μM). SIRT-IN-4 is a potent Sirt2 deacetylase inhibitor that reduces cell survival and inhibits the migration of prostate cancer cells. SIRT-IN-4 can be used to study Sirt2 in cell cycle regulation, gene expression regulation, etc.