APC and Familial adenomatous polyposis: For example, a greater diversity of methylation patterns was shown in the nonexpressed NKX2-5 gene (also known as CSX) in the crypts of normal-appearing mucosa of familial adenomatous polyposis (FAP) patients, who have a germline mutation in the APC gene that inhibits Wnt activation, compared with colons of normal controls, indicating that stem cells were present for a prolonged period in FAP patients during which they acquired these methylation events.