SOD1 and amyotrophic lateral sclerosis: Misfolding and aberrant deposition of SOD1 are thought to be responsible for ER stress in ALS cases since mutant SOD1 is prone to misfold, co-localize with ER resident markers like glucose-related protein 78 (Grp78) and calnexin (Wate et al., 2005; Kikuchi et al., 2006).