Eligible patients (≥20 years) with stage IIIB/IV or recurrent non-small-cell lung cancer and confirmed activating mutations of EGFR (exon 19 deletion or L858R point mutation in exon 21) received oral erlotinib 150 mg/day until disease progression or unacceptable toxicity. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.