EGFR and non-small cell lung carcinoma: Given that IFN-γ secreted by CD8 + T cells can regulate the expression of PD-L1, we speculate that the different expression of PD-L1 between EGFR wild-type and EGFR mutated NSCLC is related to the infiltration of CD8 + T cells, in addition to EGFR activation pathways.