Sporadic colon cancer is frequently characterized by mutation of the APC tumor suppressor, while autosomal dominant inheritance of a mutant APC allele, as in Familial Adenomatous Polyposis (FAP), results in early onset massive colonic polyposis that uniformly progresses to colorectal cancer unless prophylactic total colectomy is performed [1]. The gene discussed is APC; the disease is Familial adenomatous polyposis.