Currently, several HDAC inhibitors have been approved by FDA for the treatment of hematological malignancies, including vorinostat (SAHA), belinostat (PXD-101), romidepsin (FK-228) and Panobinostat (LBH589).2–4 However, HDAC inhibitors have shown limited success in the treatment of solid tumors.5 This evidence concerns the gene HDAC9 and hematologic disorder.