One hundred and fourteen patients (mean ± SD: 59.05 ± 11.2, range 36–85, male 43.9%) with metastatic NSCLC (stage IV) received EGFR-TKIs as first-line treatment between 1st January 2008 and 31st October 2013 were included in this study. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.