May be involved in guiding growing axons towards their targets by forming a molecular boundary that instructs axons to engage in the formation of specific nerve tracts. Binds to neuropilin. Involved in the development of the olfactory system and in neuronal control of puberty (By similarity). Interacts with PLXND1. Expressed in the dorsal root ganglia. At E11, expression was restricted to the olfactory pit, the basal and rostral surface of the telencephalic vesicle, the eye anlage, the epithelium of Rathke pouch, and somites. At later developmental stages, it was widely distributed in neuronal as well as in mesenchymal and epithelial structures outside the nervous system. After birth, mesenchymal levels decreased rapidly and expression became restricted to specific sets of neurons in the CNS. In the mature CNS, it is detectable in mitral cells, neurons of the accessory bulb and cerebral cortex, cerebellar Purkinje cells, as well as a subset of cranial and spinal motoneurons. General decrease in dorsal root ganglia in response to injury from dorsal rhizotomy, with the greatest decrease evident 21 days post-injury, returning to comparable levels 1 year post-injury (PubMed:28270793). Decreased in dorsal root ganglia in response to sciatic nerve transection 3 days post-injury, returning to comparable levels 14 days post-injury (PubMed:28270793). Strong binding to neuropilin is mediated by the carboxy third of the protein. Belongs to the semaphorin family.