Antigens that are associated with embryonic and fetal development such as these can be classified as oncofetal antigens and include commonly-used cancer serum biomarkers (eg. alpha-fetoprotein (AFP) for hepatocellular cancer and germ cell tumors, carcinoembryonic antigen (CEA) for colorectal cancer, sialylated Lewis A antigen (CA19-9) for pancreatic cancer and Mucin 16 (CA-125) for ovarian cancer. This evidence concerns the gene CEACAM5 and colorectal cancer.