[6] These Nrp-plexin and semaphorin complexes initiate cascades that regulate diverse processes such as axon pruning and repulsion, dendritic attraction and branching, regulation of cell migration, vascular remodeling, and growth cone collapse.

[7][9] Additionally, Sema3A and therefore its receptor, Plexin A4, have been implicated as possible components of fast-fatigable muscle fiber denervation in ALS.

[10] Plexin A4 has ~1890 amino acids that include a likely signal sequence, transmembrane domain, and 12 extracellular N-linked glycosylation sites.

[12] Plexin A4 has been found in dorsal and, to a greater extent, ventral horns of the spinal cord.

Motor axons exiting via the ventral roots and the ascending and descending white matter tracts express Plexin A4.