CTLA4 and melanoma: Metastatic melanoma treatment is unsatisfactory, even with the current optimized targeted therapy (BRAF-oncogene inhibitors) or immune checkpoint inhibitors (anti-cytotoxic T-lymphocyte-associated antigen 4 (anti-CTLA4), anti-programmed death-1 protein (anti-PD1), and programmed death ligand-1 protein (anti-PDL1)).