Along with dyf-7, enables neurite growth and maintenance by anchoring amphid dendritic tips during neuron cell body migration in embryonic and larval development (PubMed:19344940). Promotes seam cell remodeling during the dauer phase (PubMed:30409788). Plays a role in positively regulating locomotion during the dauer phase (PubMed:30409788). Located at dendritic tips. When transmembrane anchor domain is absent, secreted in vitro. Expression is first apparent in bean-stage embryos, peaks in late embryogenesis, reduces in L1 larvae and is negligible in later larval stages and adults (PubMed:19344940). In the embryo, expressed in the excretory cell and, during dendrite formation, in the non-neuronal cells surrounding the sensory neurons, including hypodermal cells (PubMed:19344940). Expressed in pharyngeal cells throughout the larval stages (PubMed:30409788). Expression in the seam cells and glia socket cells of the anterior and posterior deirid neurons begins at the L2 pre-dauer stage and persists throughout the dauer phase (PubMed:30409788). During the dauer phase expressed along the length of the animal above seam cells, alternating between alae under the outer ridges and below the lateral ridge (PubMed:30409788). May be proteolytically cleaved and secreted.