CD274 and neoplasm: A plethora of studies, including the CheckMate 067 trial, highlight the fact that the level of PD-L1 expression alone is a poor predictive biomarker, for which approximately 20% of patients whose tumours have minimal or no PD-L1 expression may achieve an objective response to anti-PD-1/PD-L1 treatment [71,73,74,75,76].