Mutations in several dozen genes including SOD1 [87], TDP-43 [45, 98], and C9orf72 [19, 84] have been implicated in disease pathogenesis, however for > 79% of patients the cause of disease remains unknown [52], suggesting that yet-to-be-uncovered mechanisms significantly contribute to the majority of ALS cases. This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.