In this study, extensive gene and immunohistochemical profiling confirmed that the derived Cos represent the colon rather than the small intestine, the author applied this strategy to iPSCs derived from patients with familial adenomatous polyposis harboring germline mutations in the WNT-signaling-pathway-regulator gene encoding adenomatous polyposis coli (APC), and Cos exhibits enhanced WNT activity and increased epithelial cell proliferation, which was used as a platform for colorectal cancer model and drug testing [102]. The gene discussed is APC; the disease is colorectal cancer.