EGFR and lung adenocarcinoma: Gefitinib is an FDA-approved selective inhibitor of EGFR TKI,28 which is initially used as an effective treatment for advanced non-small cell lung cancer (NSCLC).29,30 Gefitinib was applied at a dose of 250 mg daily in lung adenocarcinoma patients,31 which was equivalent to 32.5 mg/kg in mice.