The Wnt family of consists of ligands involved in cell development, fate determination, organogenesis and oncogenesis. Information on Wnt signaling has been inferred from genetic analysis of wingless (wg) signaling in Drosophila. The Wnt signaling cascade initiates at the cell membrane when Wnt interacts with its receptor, a member of the Frizzled (Fz) transmembrane receptor family and lipoprotein receptor-related proteins 5 and 6 (LRP-5/6). This interaction relays the signal into the interior of the cell where disheveled (dsh) is brought to the membrane and gets phosphorylated/activated. Dsh promotes the inactivation of GSK3 kinase activity, thus preventing the phosphorylation of beta-Catenin and allowing it to accumulate as it avoids ubiquination and subsequent proteosome degradation. Stable beta-Catenin accumulates in the cytoplasm where it interacts with lymphoid enhancer factor/T cell factor (LEF/TCF) and translocates into the nucleus. This results in activation of TCF-responsive genes which are thought to play key roles in development and cancer. Negative regulators of the pathway may include axin and the tumor suppressor APC.