Although atezolizumab as first-line monotherapy showed clinical survival benefit in patients with NSCLC with high PD-L1 expression 8, the OAK trial revealed that patients with previously treated metastatic NSCLC have survival benefit from atezolizumab treatment regardless of PD-L1 expression, histology, or EGFR mutation status 12. This evidence concerns the gene EGFR and non-small cell lung carcinoma.