et al showed that the 5-year survival of patients with preoperative serum CEA level less and more than 2.5 ng/ml were significantly different as 79.62% and 62.0%, respectively (P = 0.0036), which indicated that a preoperative serum CEA level of ≥2.5 ng/ml was an independent prognostic factor for NSCLC patients [12]. The gene discussed is CEACAM5; the disease is non-small cell lung carcinoma.