Involved in the development of primary sensory neurons especially in branching of the peripheral axons. Interacts with the SLIT2 signaling specifically to promote axonal branching of Rohon-Beard neurons and the trigeminal sensory ganglion neurons. In the embryonic brain expressed in specific subtypes of neurons. Found in the tectal region, hindbrain, neurons in the nucleus of the anterior commissure, posterior commissure, postoptic commissure, medial lateral fascile and epiphysis. Localized to both central and peripheral axons of the primary sensory neurons. Belongs to the plexin family.