Traditional tumor serological markers such as cancer antigen 12-5 (CA12-5), carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCCA), and carbohydrate antigen199 (CA19-9) are used as auxiliary markers of clinical diagnosis for EC, but the sensitivity and specificity of these markers are poor (Kosugi et al., 2004; Mroczko et al., 2008). The gene discussed is CEACAM5; the disease is neoplasm.