CD274 and neoplasm: Preliminary data suggesting that tumor PD-L1 expression could be a predictive biomarker of response to nivolumab 19 were later supported by an observation that 0/17 nivolumab-treated patients with PD-L1− tumors experienced ORs, whereas 9/25 patients with PD-L1+ tumors (36%) achieved ORs (P = 0.006).