Recent insights from diverse fields of basic and clinical research reveal that the biological processes that govern embryonic development and organogenesis are also commonly involved in the pathologies that arise in that organ or tissue in the adult. This striking parallel between embryonic development and pathology is exemplified by Wnt signalling in the intestinal tract. Wnt signalling is critical throughout embryonic development of the mammalian gut. Moreover, competent Wnt signalling is essential for the homeostatic control of the adult intestinal epithelium. On the other hand, aberrant Wnt signalling in the adult intestine leads to cancer and other pathologies. This critical role of the Wnt pathway in gut development and homeostasis is conserved through evolution, emphasizing the importance of this pathway in this tissue. Interestingly, expression of the Wnt receptor FZD7 in gut tissue is also conserved through evolution, suggesting that this receptor may be integral to the important role assigned to Wnt signalling in gut tissues.