Wnt-1 is a secreted protein that signals through the frizzled family of seven transmembrane receptors. Wnt-1 activation induces a complex signaling cascade that ultimately leads to the up-regulation of over fifty genes. Stabilization and resulting accumulation of the intracellular signaling protein _-catenin is an important aspect of Wnt-1 signaling. While known to play in role as a developmental protein, elevated levels of Wnt proteins have also been associated with tumorigenesis.