Ligand for members of the frizzled family of seven transmembrane receptors that functions in the canonical Wnt/beta-catenin signaling pathway (By similarity). Plays an important role in embryonic development, including dorsal versus ventral patterning during limb development, skeleton development and urogenital tract development. Required for central nervous system (CNS) angiogenesis and blood-brain barrier regulation (By similarity). Required for normal, sexually dimorphic development of the Mullerian ducts, and for normal fertility in both sexes. Required for normal neural stem cell proliferation in the hippocampus dentate gyrus. Required for normal progress through the cell cycle in neural progenitor cells, for self-renewal of neural stem cells, and for normal neuronal differentiation and maturation. Promotes formation of synapses via its interaction with FZD5 (By similarity). Forms a soluble 1:1 complex with AFM; this prevents oligomerization and is required for prolonged biological activity. The complex with AFM may represent the physiological form in body fluids (By similarity). Interacts with FZD5. Interacts with PORCN (By similarity). Interacts (via intrinsically disordered linker region) with RECK; interaction with RECK confers ligand selectivity for Wnt7 in brain endothelial cells and allows these cells to selectively respond to Wnt7 (By similarity). The intrinsically disordered linker region is required for recognition by RECK in brain endothelial cells. Palmitoleoylation is required for efficient binding to frizzled receptors. Depalmitoleoylation leads to Wnt signaling pathway inhibition. Belongs to the Wnt family.