CD274 and non-small cell lung carcinoma: In NSCLC, based on PD-L1 IHC 22C3 pharmDx assay performed by Hwang et al., intra-tumoral heterogeneity is related to an increase in the proportion of patients with high PD-L1 expression in metastatic site biopsies and might result in the misjudgment of PD-L1 status (45).