We retrospectively collected the clinical information of advanced lung adenocarcinoma patients harboring EGFR mutation, who received EGFR-TKIs as first-line therapy from June 2009 to June 2014 in Peking University Cancer Hospital, analyzed the relationship between serum tumor markers and efficacy of EGFR-TKIs. The gene discussed is EGFR; the disease is lung adenocarcinoma.