C9orf72 and amyotrophic lateral sclerosis: Interestingly, more candidates genes including TDP-43 gene, FUS gene and the most recent and most common C9orf72 gene expansion, which phenotype is distinctively different from other forms of ALS have been reported more frequently; but animal models-when they exist- do not mimic clinical phenotypes of ALS as closely as SOD1 mouse [5].