CEACAM5 and Familial adenomatous polyposis: The finding of an inverse relationship between CEA and BGP is a novel finding in the CTT however, a seminal paper on familial adenomatous polyposis in humans compared the expression profiles of these two antigens in neoplastic tissue of varying dedifferentiation and found twofold decrease in BGP expression in the more differentiated mucosa whereas CEA levels were only 30% higher than normal mucosa in the equivalent tissue [48].