PDCD1 and melanoma: Anti-CTLA-4 (e.g., ipilimumab) and anti-PD-1 (e.g., pembrolizumab, nivolumab) monoclonal antibodies, both as monotherapy and in combination regimens, have become a standard of care treatment option in patients with melanoma, renal cell carcinoma, non-small cell lung cancer, urothelial cancer, and Hodgkin lymphoma.