EGFR and adenocarcinoma: The incidence of lung cancer is increasing in Taiwan, and lung cancer is the leading cause of cancer-related deaths worldwide.[1–4] Relatively high incidences of epidermal growth factor receptor (EGFR) mutations have been reported among patients with an Asian lineage, never smokers, and cases of adenocarcinoma.[5–7] Nevertheless, EGFR-tyrosine kinase inhibitors (TKIs) improve progression-free survival (PFS), overall survival (OS), and quality of life outcomes among non-small cell lung cancer (NSCLC) patients harboring EGFR mutation.