SOD1 and amyotrophic lateral sclerosis: Moreover, SOD1 intracellular aggregation, which causes specific degeneration of motor neurons (Gurney et al., 1994), has been observed in sporadic ALS cases without SOD1 mutation (Bosco et al., 2010; Forsberg et al., 2010; Guareschi et al., 2012; Pokrishevsky et al., 2012; Paré et al., 2018).