Immune checkpoint inhibitors (ICI) that target cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have significantly transformed the treatment of a variety of cancers, such as melanoma, lung and genitourinary cancers. The gene discussed is PDCD1; the disease is urogenital neoplasm.