Carcinoembryonic antigen (CEA)5, carbohydrate antigen 19-9 (CA19-9)6, carbohydrate antigen 125 (CA125)7, and alpha-fetoprotein (AFP)8 can be elevated in CRC patients, making them widely employed in the diagnosis and monitoring of CRC. This evidence concerns the gene CEACAM5 and colorectal carcinoma.