The blockade of the immune checkpoint pathway involving the programmed death 1 (PD-1) receptor and its ligands, CD274 (PD-L1) and CD273 (PD-L2), has recently been shown to be effective in the treatment of various cancers, including urothelial carcinoma (UC) [7,8,9]. The gene discussed is PDCD1LG2; the disease is cancer.