Lung cancer is the leading cause of cancer-related death worldwide and in Taiwan, and the incidence of lung cancer in Taiwan is increasing.[1, 2] Epidermal growth factor receptor (EGFR) mutations are more common in Asian patients with non-small cell lung cancer (NSCLC) compared with non-Asians, in non-smokers compared with current or ex-smokers, and in adenocarcinoma compared with other cancer histologies.[3–5]. This evidence concerns the gene EGFR and adenocarcinoma.