Frizzled-3

Among the ten Frizzled Wnt receptors, Frizzled-3 (FZD3) stands out for its prominent role in the nervous system. Its extracellular CRD binds several Wnt ligands, and signaling proceeds largely through non-canonical planar cell polarity effectors rather than robust beta-catenin activation. Fzd3-deficient mice show defective neural tube closure, abnormal axon trajectories and impaired commissure formation, and the receptor guides neural crest cell migration and cranial nerve patterning during embryogenesis. In adults, FZD3 expression persists in the brain and is also detected in endothelial cells of the blood-brain barrier. Because dysregulated FZD3 expression correlates with progression in cancers such as colorectal carcinoma and neuroblastoma, it is being evaluated as a therapeutic antibody target.