Ligand for members of the frizzled family of seven transmembrane receptors. Probable developmental protein. May be a signaling molecule which affects the development of discrete regions of tissues. Is likely to signal over only few cell diameters. Involved in the correct positioning of the developing nerve ring and in axon guidance of SIA and SIB neurons, probably by binding to tyrosine kinase receptor cam-1 (PubMed:19855022). In addition, regulates the positioning of some head neuronal cells, muscle arms associated with the nerve ring and the excretory pore (PubMed:19855022). Together with Wnt ligand cwn-1, regulates the migration of CAN, ALM, BDU and HSN neurons during embryogenesis, the migration of QL and QR neuroblast descendants during larval development, and polarity of ALM neurons (PubMed:16109397, PubMed:16516839, PubMed:18622031, PubMed:25917219). May act through the wnt receptor cfz-2 to regulate QR neuroblast descendant migration, and to direct ALM migration (PubMed:16109397). Also plays a role in axon growth and guidance in HSN and male CP neurons (PubMed:16109397). In addition, together with wnt ligand cwn-1, negatively regulates developmental neurite pruning of AIM neurons probably by acting as a ligand for receptor tyrosine kinase cam-1 (PubMed:19561603). Through the cam-1 receptor also probably regulates the outgrowth of neurites from RME GABAergic motor neurons (PubMed:20711352). May act redundantly with other Wnt ligands such as cwn-1 and mom-2 to control seam cell polarity (PubMed:22022276). Expressed in intestine, pharynx, anterior body wall muscle, vulva, some pharyngeal neurons and SMD head neurons (PubMed:19855022, PubMed:19561603, PubMed:22022276). Expressed along the boundary between the intestine and muscle or hypodermis, but is also expressed in the hypodermis in cells including seam cells (PubMed:22022276). Expressed at the comma stage in pharyngeal muscles and the developing intestine (PubMed:19855022). Detected in all larval forms and adults, but is most abundant in the embryonic stage (PubMed:8510930). At the two-fold stage of embryogenesis, mainly it is expressed in the intestine (PubMed:20711352). During late embryogenesis, before hatching, it is expressed in the posterior pharyngeal bulb and the pharyngeal-intestine (PubMed:20711352). After the L1 stage of larval development it is expressed in the anterior part of the animal in tissues including the pharynx, body wall muscle and ventral cord neurons (PubMed:20711352). Palmitoleoylation is required for efficient binding to frizzled receptors. Depalmitoleoylation leads to Wnt signaling pathway inhibition. Anterior displacement of the nerve ring in L1 stage mutant animals (PubMed:19855022). Defective ALM, BDU, CAN and QR neuroblast migration and irregular CP and CAN axon growth and guidance (PubMed:16109397). Double knockout with cfz-2 results in enhanced CAN migration defects, but the same QR neuroblast migration defects as the single cfz-2 knockout alone (PubMed:16109397). Double knockout with cwn-1 results in ALM, CAN and HSN migration defects (PubMed:16109397, PubMed:16516839). Triple knockout with cwn-1 and cfz-2 results in enhanced neuronal cell migratory defects (PubMed:16109397). Belongs to the Wnt family.