Prior trials confirmed that the response rate to EGFR-TKI in NSCLC patients with EGFR mutations is approximately 70–80% [12,19,20], and results of recent phase III trials showed that the oral EGFR-TKI gefitinib has a superior progression-free survival (PFS) to standard chemotherapy as the first-line therapy for NSCLC with mutated EGFR[21,22]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.