PDCD1 and melanoma: For example, anti-programmed cell death-1 (anti-PD-1), anti-programmed death-ligand 1 (anti-PD-L1), or anti-cytotoxic T-lymphocyte associated protein 4 (anti-CTLA4) have been generally used for non-small cell lung cancer (NSCLC), bladder cancer, heck and neck squamous cell cancer, renal cell carcinoma, melanoma, classical Hodgkin lymphoma, and ovarian cancer [1, 33, 34].