a secreted glycoprotein patterning switch with different roles in different tissues. The name was derived from two drosophila phenotypes ' w ingless' and 'i nt ' and the gene was first defined as a protooncogene, int1. Humans have at least 4 WNT genes encoding secreted glycoproteins with at least one wnt receptor called Frizzled (FZD). Wnt7a is secreted protein and binds to extracellular matrix. The mechanism of Wnt distribution (free diffusion, restricted diffusion and active transport) and all its possible cell receptors are still being determined. In the gastrointestinal system, Wnt maintains the pool of undifferentiated intestinal progenitor cells and control maturation and correct positioning of the Paneth cell (a differentiated intestinal cell type).