Aberrant histone acetylation has been shown to affect tumor cells and tumor-infiltrating lymphocytes by regulating the TRAIL/Apo2L apoptotic pathway or proapoptotic proteins from the Bcl-2 family (Bim, Bax, and Bak) in melanoma, highlighting the therapeutic potential of HDAC inhibitors in melanoma [94]. This evidence concerns the gene HDAC9 and neoplasm.