PDCD1 and neoplasm: Immunotherapy has significantly progressed, utilizing immune checkpoint inhibitors such as Programmed Cell Death Protein-1/Programmed Death-Ligand 1(PD-1/PD-L1) and Cytotoxic T-lymphocyte-associated protein 4(CTLA-4) antagonists, among others, to amplify the immune system’s capacity to counteract tumor growth (8).