C9orf72 and amyotrophic lateral sclerosis: Exposure of transgenic animals with common ALS genetic defects, such as the SOD1G85R mutation or the genetic expansion within the first intron of the C9orf72 gene to oxidative stress, displays key ALS-related phenotypes: the aberrant aggregates related to SGs in motor neurons, accompanied by locomotor defects in the animals, that arise secondary to muscle dysfunction.