[Non-canonical Wnt signaling and cellular responses.]

Non-canonical Wnt signaling, including planar cell polarity and Ca²⁺ pathways, plays crucial roles in developmental processes, including morphogenesis and tissue-/organo-genesis, in animals. Ror2 receptor tyrosine kinase mediates non-canonical Wnt signaling by acting as a receptor for Wnt5a, which also inhibits canonical Wnt signaling. Dysregulation of Wnt5a-Ror2 signaling causes a wide range of developmental defects and cancer progression. Recently, Ror2-mediated non-canonical Wnt signaling has also been shown to induce formation of filopodia that facilitates transport of Wnt to neighboring cells, thereby activating canonical Wnt signaling there.