PDCD1 and melanoma: Very recent advances in molecular oncology have indeed yielded new treatment strategies that target either key effectors of the pathways found to play a major role in the pathogenesis of melanoma – such as those depending on activation of BRAF, NRAS, or cKIT genes – either immune regulatory molecules involved in suppression of the antitumor immune response – such as T-lymphocyte-associated antigen 4 (CTLA4), programed cell death 1 (PD-1), and its ligand (PD-L1) (5).