Colonic crypt organization and tumorigenesis.

An appreciation of colonic crypt organization has become essential to any understanding of tumorigenesis in the colon. Intestinal crypts house tissue-specific, multipotential stem cells, which are located in the niche at the base of the intestinal crypt and are capable of regenerating all intestinal cell types. Recent advances in our understanding of crypt biology, including how mutations in stem cells become fixed and expand within the epithelium, has led to new theories on the origins of colonic adenomas and cancers.