Five HDAC inhibitors (Vorinostat, Belinostat, Romidepsin, Tucidinostat and Panobinostat) have been approved to treat both lymphomas and myelomas, with more pan‐ and selective inhibitors under clinical trials for various cancers and non‐oncogenic diseases, including inflammatory disease, neurodegenerative disease and muscular dystrophy [182]. This evidence concerns the gene HDAC9 and cancer.