Actually, 3 immune checkpoint inhibitors (ICIs) have been approved for treatment advanced melanoma patients: ipilimumab, a monoclonal antibody against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4); the anti-programmed cell death receptor 1 (PD-1) agents pembrolizumab and nivolumab; as well as the combination of ipilimumab plus nivolumab [78]. Here, CTLA4 is linked to melanoma.