Soluble frizzled-related proteins (sFRPS) function as modulators of Wnt signaling through direct interaction with Wnts. They have a role in regulating cell growth and differentiation in specific cell types. SFRP3/FRZB appears to be involved in limb skeletogenesis. Antagonist of Wnt8 signaling. Regulates chondrocyte maturation and long bone development. At stage 7 of embryonic development, expressed in the neural plate with lower expression in the midline. At stage 9, expression restricted to the dorsal neural tube and cranial neural crest. At stage 12, expressed in the lateral plate mesoderm. In the developing trunk, expressed, from stages 9-12, in the ventral migrating neural crest with some expression at stage 12 in the dorsal streams From stage 15, expressed in the endocardial cells of the outflow tract of the developing heart. From stage 18, expression found in the epibranchial placodes, in endocardial and mesenchymal cells of the developing atrioventricular canal and of the outflow tract cushions. Expression in these regions of the developing heart continue until stage 26. During limb development, low expression found, by stage 18, in the developing limb buds, By stage 20, highly expressed in the ventral mesenchyme of both fore- and hind-limb buds. By stage 24, expression localized to the central core of the developing limb bud, which contains the chondrogenic precursors. Also expressed in the surrounding nonchondrogenic mesenchyme. Later expression confined to the perichondrium and to the epiphyses of the early developing skeletal elements. The FZ domain is involved in binding with Wnt ligands. Belongs to the secreted frizzled-related protein (sFRP) family.