EGFR and non-small cell lung carcinoma: Some literatures[8,33] reported that PD-L1 expression was reduced in NSCLC cell lines by activating EGFR, meanwhile some researchers[34] found that EGFR—tyrosine kinase inhibitors (TKIs) could indirectly enhance anti-tumor immunity through the down-regulation of PD-L1, which might explain the reverse effect of EGFR and PD-L1.