SOD1 and amyotrophic lateral sclerosis: Mutant Superoxide dismutase 1 (SOD1) was the first gene identified to be involved in familiar ALS (Rosen et al., 1993), and the high penetrance allele SOD1G93A (Synofzik et al., 2010) has been employed to generate the most extensively used ALS-mouse model (Gurney, 1997).