HDAC-IN-51 is a potent histone deacetylase ( HDAC ) inhibitor with IC 50 values of 0.32, 0.353, 0.431, 0.515, and 85.4 μM for HDAC10 , HDAC1 , HDAC2 , HDAC3 and HDAC11 , respectively. HDAC-IN-51 induces cell cycle arrest and apoptosis , modulating cell cycle-/apoptosis-related miRNAs expression. HDAC-IN-51 can be used in research of cancer.