Gefitinib, one of the widely used EGFR-TKIs, has been approved for the first-line treatment of NSCLC with sensitizing EGFR mutations (exon 19 deletion or L858R point mutation) (8), while drug resistance in cancer cells contributes to the limited clinical efficacy of the targeted drug. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.