SIGMAR1 and amyotrophic lateral sclerosis: Many mutated genes associated with ALS are linked to the proteasome and autophagy, including C9ORF72, OPTN, VCP, SIGMAR1, PARK9, SQSTM1, CHMP2B, UBQLN2 and FIG4, indicating that dysfunctional proteostasis may also induce ALS.