Tgfb mRNA levels are further increased with the administration of an anabolic/androgenic steroid (AAS), indicating that, at least at the muscular level, AAS might exert a detrimental role in ALS, since it might exacerbate some of the alterations induced by mutSOD1 [28,88]. This evidence concerns the gene TGFB1 and amyotrophic lateral sclerosis.