CTLA4 and melanoma: Since the discovery of the BRAFV600 mutations in malignant melanoma, the development of new drugs, including effective small molecule inhibitors of the MAPK signalling pathway, antibodies targeting immune checkpoint inhibitors including cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death (PD)-1, and PD-ligand 1 (PD-L1), has expanded dramatically [17,18].