Functions as a cell surface repellent for mossy fibers of developping neurons in the hippocampus where it plays a role in axon guidance. May function through the PLXNA4 receptor expressed by mossy cell axons. Detected in the first branchial arch of embryonic day 11 (E11) embryo, and subsequently in the myotomes and the dorsal root ganglia in developing somites from E11.5 through E13.5, but not in the brain. However, at E15, 18, 21 and P0, highly expressed in the brain. Belongs to the semaphorin family.