In recent years, multiple Phase-III clinical studies (IPASS, NEJGSG, WJTOG3405, First Signal, Optimal, etc.)have shown that tyrosine kinase inhibitor (TKI), such as gefitinib or erlotinib, are effective as first-line treatment in patients with epidermal growth factor receptor (EGFR) mutation, and are associated with good response rate, longer progression free survival (PFS), and better quality of life compared to standard chemotherapy.4,5 Therefore, EGFR-TKI has been approved for first-line treatment in NSCLC patients with positive EGFR gene mutations. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.