First approved in 2011 for targeting anti-cytotoxic T lymphocyte-associated protein 4 (anti-CTLA-4) in advanced melanoma, Ipilimumab was soon followed in 2014 by two anti-programmed cell death protein 1 (anti-PD-1) agents, Pembrolizumab and Nivolumab. Here, CTLA4 is linked to melanoma.