Most HDAC inhibitors identified to date are hydroxamate derivatives, including the three novel HDAC inhibitors, vorinostat (suberoylanilide hydroxamate, SAHA) (Grant et al., 2007), belinostat (PXD101) (Poole, 2014) and panobinostat (LBH589) (Cheng et al., 2015) which have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of various hematologic malignancies. This evidence concerns the gene HDAC9 and hematologic disorder.