Mocetinostat is an orally available inhibitor of histone deacetylases (HDACs) that selectively targets HDAC1 and 2 (IC50s = 0.15 and 0.29 μM, respectively), less potently inhibits HDAC3 and 11 (IC50s = 1.66 and 0.59 μM, respectively) and has negligible actions against HDAC4-8. It induces hyperacetylation of histones, causes cell cycle blockade, and induces apoptosis in cancer cells in vitro. Mocetinostat also has antitumor activity in vivo, blocking the growth of human tumor xenografts in mice. It also significantly reduces cardiac fibrosis following ischemic heart failure in mice.