HDAC inhibitors appear to reestablish apoptosis in melanoma cells [30], induce cell differentiation, and inhibit tumor growth in animal models by down-regulating positive cell cycle regulators such as cyclin D1, c-Myc, C-RAF, and AKT [31–37], while inducing the expression of a number of anti-proliferative genes [38–40]. This evidence concerns the gene HDAC9 and melanoma.