PDCD1 and melanoma: Monoclonal antibodies directed against PD-1 (Nivolumab, Pembrolizumab, Cemiplimab, Spartalizumab, Camrelizumab, Sintilimab) or PD-L1 (Atezolizumab, Durvalumab, Avelumab, SHR-1316) are now used regularly for the treatment of multiple types of solid tumors, such as non-small cell lung cancer (NSCLC), melanoma, and gastric cancers to cite only a few types [1].