EGFR gene mutations are mainly in patients with advanced NSCLC, nonsmokers, lung adenocarcinoma patients, patients with lymph node metastasis, patients with high CEA expression, and patients with low Cy21-1 expression are more likely to develop EGFR mutation, and EGFR mutation patients have a better prognosis. This evidence concerns the gene CEACAM5 and lung adenocarcinoma.