EGFR and non-small cell lung carcinoma: In the case of epidermal growth factor receptor (EGFR) mutation, EGFR-mutant NSCLC patients have displayed a lower chance of PD-L1 expression and a strong PD-L1 expression has been reported to correlate with a worse outcome of EGFR-tyrosine kinase inhibitor (TKI) treatment13–15.