They activate the canonical Wnt cascade as well as the non-canonical Wnt pathways. Wnt genes and signaling components are found in all metazoan animals, including sponges (Clevers and Nusse 2012), and have a widespread activity.
They are involved in maintaining stem cells in many organisms. However, to date the underlying mechanisms haven’t been fully understood. It is assumed that Wnt signals suppress differentiation-specific genes.
Wnt pathway mutations, especially Wnt, APC, axin and TCF alterations, are frequently observed in cancer. Some metabolic diseases like type II diabetes have been linked to the Wnt pathway as well (Clevers and Nusse 2012; Polakis 2012).