Involved as a receptor for mab-20/sema-2a in the formation or stabilization of cell-cell contacts at several stages of epithelial morphogenesis (PubMed:17507686). In early embryonic development, required for proper ventral closure of the epidermis (PubMed:17507686). During male tail morphogenesis, involved in precursor cell sorting and in the formation of distinct sensory rays (PubMed:15030761). Involved in axon guidance of SDQL neurons during neurogenesis (PubMed:26903502). Probably in response to stimulation by mab-20, regulates fln-1-mediated remodeling of the actin cytoskeleton and thus axon guidance and/or fasciculation of DD/VD neurons (PubMed:25358863). Interacts with mab-20. Expressed predominantly in the central nervous system from embryonic to adult stages. Expressed in early embryos in ventral neuroblasts. Expressed in neurons and in a subset of posterior lateral and ventral epidermal cells following epidermal enclosure. Present in neurons, muscles and weakly expressed in epidermal cells of the larval tail. Belongs to the plexin family.