Pracinostat dihydrochloride is a potent histone deacetylase ( HDAC ) inhibitor, with IC 50 s of 40-140 nM, used for cancer research. Pracinostat dihydrochloride also inhibits metallo-β-lactamase domain-containing protein 2 ( MBLAC2 ) hydrolase activity with an EC 50 below 10 nM.