Binds as a ligand to a family of frizzled seven-transmembrane receptors and acts through a cascade of genes on the nucleus. Acts downstream of homeotic complex genes in the visceral mesoderm and is required for embryonic segmentation. Also required for cell movement and FAK regulation during ovarian morphogenesis. Palmitoleoylated by porcupine. The lipid group functions as a sorting signal, targeting the ligand to polarized vesicles that transport Wnt4 to unique sites at the cell surface. Depalmitoleoylated by notum, leading to inhibit Wnt signaling pathway. Belongs to the Wnt family.