CEACAM5 and colorectal carcinoma: Subsequent studies suggested that CEA was also found in healthy tissues, although its concentration in tumor tissues was 60 times higher than that in non‐tumor tissues.23 The CEA gene was recently classified as an immunoglobulin gene super family member.24 One recent research showed CEA was a glycoprotein associated with colorectal cancer (CRC) and the changing CEA glycosylation patterns and their role in the development of CRC highlight the importance of glycan variants on CEA for early clinical detection and staging of CRC.25