Particularly, monoclonal antibodies targeting programmed cell death 1 (PD-1) and its ligand, programmed cell death ligand 1 (PD-L1), have revolutionized the landscape of malignant skin cancer.[38] The PD-1/-L1 pathway plays a critical role in tumor immune evasion across a broad range of tumor types. The gene discussed is PDCD1; the disease is neoplasm.