HDAC9 and cancer: Both HDAC inhibitors (HDACi) and inhibitors of Bromodomain and Extra-Terminal motif (BET) protein, which are required for the recognition of acetylated lysine residues in histones, have been shown to have anti-tumour activities against numerous Myc-amplified cancers including neuroblastomas, acute myeloid leukemia, myeloma and prostate cancer [55,56,57,58].