During the study period, 48 patients with stage IV lung adenocarcinoma harboring susceptible EGFR mutations who received afatinib as the first-line therapy were enrolled (Table 1), of whom 29 (60.5%) and 19 (39.5%) received 30 mg and 40 mg daily as their initial treatment, respectively. This evidence concerns the gene EGFR and lung adenocarcinoma.