Acts as a receptor for slt-1 (PubMed:17901337). Required for the guidance of the AVM pioneer axon to the ventral nerve cord (PubMed:17901337). Acts as a unc-40 coreceptor to enhance the sensitivity of unc-40 to the madd-4 midline guidance cue to guide muscle arm extensions (muscle arms) and AVM mechanosensory axons towards the dorsoventral midline (PubMed:25122090). Interacts with sax-3 (PubMed:17901337). Interacts with slt-1 (PubMed:17901337, PubMed:25122090). Interacts (via the SUEL-type lectin domain) with madd-4 (PubMed:25122090). Interacts (via the transmembrane domain) with unc-40 (PubMed:25122090). Widely expressed in the developing nervous system during the period of embryogenesis. In first-larval-stage animals, strong expression is observed in ventral and dorsal nerve cords and in the PVM neurons but not in the AVM neurons. The SUEL-type lectin domain, the transmembrane domain and the C-terminal region are required for the guidance of the muscle arm extensions to the midline neurons. Belongs to the EVA1 family.