NRP1 and amyotrophic lateral sclerosis: Finally, to validate our finding with other ALS models and to emphasize the impact of Sema3A in ALS, we performed Western blot analysis for Sema3A and NRP1 expression in human mesenchymal stem cells from sporadic ALS patients and healthy controls, as well as in myocyte-expressing C9orf72-PR50 and their CM for Sema3A.