– Ligand for members of the frizzled family of seven transmembrane receptors. Functions in the canonical Wnt/beta-catenin signaling pathway. Plays a role in normal ectoderm development. Required for normal tooth development. Required for normal postnatal development and maintenance of tongue papillae and sweat ducts. Required for normal proliferation of basal cells in tongue filiform papillae, plantar epithelium and sweat ducts. Required for normal expression of keratins in tongue papillae. Required for normal expression of KRT9 in foot plant epithelium. Required for normal hair follicle function.