PDCD1 and neoplasm: Upon treatment with anti-PD-1 agents, skin depigmentation occurs as a result of cytotoxic T cell activation against these shared antigens, which include Melanoma antigen recognized by T cells 1 (MART-1, also called Melan-A), GP100, tyrosinase-related proteins 1 and 2 (TRP1 and TRP2), and tyrosinase [97,99].