CD274 and urothelial carcinoma: In the KEYNOTE-052 trial, a phase II study of pembrolizumab for patients with urothelial carcinoma, the objective response rate (ORR) in the group with PD-L1 expression higher than 10% was significantly better than that in the group with PD-L1 expression lower than 1% (39% vs 11%) 6.