CD274 and non-small cell lung carcinoma: Although the possible mechanisms by which PD-L1 leads to acquired resistance to EGFR-TKIs in NSCLC, including the upregulated expression of YAP1 and BAG-1 [23, 24], have been investigated in several studies, little is known about the relationship between PD-L1 and primary resistance to EGFR-TKIs or the potential molecular mechanism.