EGFR and non-small cell lung carcinoma: The present study is the first to identify that miR-27a, miR-218, and miR-27a might play a role in primary resistance to EGFR-TKI in advanced NSCLC patients with EGFR exon 19 deletion mutations treated with EGFR-TKI, independent of c-MET amplification and T790M mutation.