CD274 and non-small cell lung carcinoma: Although intratumoural PD-L1 expression can enrich for responders (e.g., NSCLC) (Reck et al, 2016), PD-L1 remains an imperfect biomarker and PD-L1 status neither guarantees nor precludes response to PD-1/PD-L1 blockade (Kluger et al, 2017).