CDK4 and melanoma: Melanoma is an immunogenic tumor that, during its progression, overexpresses several melanoma-associated antigens (e.g., MAGE, S100, tyrosinase, Melan-A/MART-1, gp100, CDK4) recognized by lymphocytes [3], and for this reason it shows, among other tumors, one of the highest sensitivity to immunotherapies [4].