Re-expression of plexin-A2 mutated in its semaphorin binding domain in plexin-A2 knock-out glioblastoma-derived cells did not abrogate rescue of cell proliferation, suggesting that the pro-proliferative effect of plexin-A2 is not activated by the binding of a semaphorin to plexin-A2 (Table 1) [53]. This evidence concerns the gene PLXNA2 and glioblastoma.