Therapy of patients with advanced melanoma has seen drastic improvements over the last years since the introduction of the checkpoint inhibitors ipilimumab (targeting the cytotoxic T-lymphocyte associated protein 4 (CTLA-4)) and nivolumab / pembrolizumab (targeting the programmed death-1 (PD-1) receptor) and their combination. Here, CTLA4 is linked to melanoma.