Since the frequently used CRC tumor markers like carcino-embryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 50 (CA50) do not possess comparatively satisfactory sensitivity or specificity in early screening, it is necessary to explore new biomarkers for early and effective diagnosis of CRC (Lech et al., 2016). The gene discussed is CEACAM5; the disease is neoplasm.