The Wnt genes belong to an ever-expanding family of proto-oncogenes that express in species ranging from Drosophila to man. Wnt proteins, as well as other growth factors or signaling molecules, have the characteristics of secreted growth factors. As recently, a group of proteins in Frizzled (Fz) family have been identified as the putative receptors of Wnt family,several components are implicated in the downstream of Wnt/Fz signaling pathway, such as Dishevelled, GSK3 (glycogen synthase kinase 3), APC (adenomatous polyposis coli) and β-catenin.This signal transduction pathway plays a pivotal role not only in the formation and organization of developing organs, but also in biological tumorigenesis.