Traditionally, serum tumor markers, such as carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC‐Ag), cytokeratin 19 fragment 21‐1 (CYFRA21‐1), and serum p53 antibody, have been widely used in the diagnosis of esophageal cancer [9, 10, 11]. The gene discussed is CEACAM5; the disease is esophageal cancer.