APC and Familial adenomatous polyposis: In the early 1990s, the Kinzler and Nishisho groups independently found the adenomatous polyposis coli (APC) gene in familial adenomatous polyposis, a hereditary cancer syndrome, which was the first connection of the Wnt signaling pathway to human disease.14,15 Later, the APC protein was found to interact with β-catenin16,17 and APC deficiency resulted in constitutively active β-catenin/TCF (T-cell factor) signaling in colon carcinoma cells.18 These findings demonstrated the close link between Wnt signaling and human disease.