Fig. 2.

PD-L1 is responsible for generating primary resistance to gefitinib. a PD-L1 mRNA and protein expression levels in stable HCC827 cell lines transfected with a PD-L1-expressing plasmid (PLVX-PD-L1) or a negative control (PLVX-NC). b PD-L1 mRNA and protein expression levels in stable HCC827 cell lines transfected with two PD-L1 ShRNAs (Sh-PD-L1–1 and Sh-PD-L1–2) or a negative control (Sh-PD-L1-NC). c and (d) Stable PD-L1-overexpressing and PD-L1-silenced HCC827 cells were treated with different concentrations of gefitinib, and the IC50 value was calculated from the dose-response survival curve determined by the CCK-8 assay. ***P < 0.001