[Canonical Wnt signaling pathway and current issues.]

The Wnt signaling pathways are classified into the β-catenin dependent pathway, which regulates gene expression through β-catenin, and the β-catenin independent pathway, which does cytoskeletal rearrangement in a β-catenin independent manner. The former is also called as the canonical Wnt signaling pathway and extensively studied in development, tumorigenesis, and regenerative research. Recently, novel mechanistic insights into the canonical Wnt signaling pathway have been clarified through the analysis of structure of Wnt-receptor complex, regulation of Wnt signaling at the cell surface membrane, and intracellular protein complex of Wnt complexes.