PDCD1LG2 and bladder transitional cell carcinoma: Furthermore, a high risk score was positively associated with the expression levels of six key immune checkpoint genes (CD274, PDCD1, PDCD1LG2, CTLA4, HAVCR2, and IDO1) and other related immune checkpoint genes, which indicates that risk score might be a target to distinguish the immunotherapy efficacy among BLCA patients.