Ligand for members of the frizzled family of seven transmembrane receptors (By similarity). Affects male tail development, vulval precursor cell specification and egg laying. Involved in morphogenesis by influencing polarity of asymmetric cell divisions of the B, U, and F cells in the male, and the T cell in males and hermaphrodites. Controls spindle orientation in B-gamma cell division during male copulatory spicule development. Involved in specification of the P7.p lineage during vulval development. Has a role in providing polarity and default lin-17 localization in axon development and positioning of neuromuscular synapses in DA9 regions by negatively regulating synaptogenesis (By similarity). Palmitoleoylation is required for efficient binding to frizzled receptors. Depalmitoleoylation leads to Wnt signaling pathway inhibition. Belongs to the Wnt family.