SOD1 and amyotrophic lateral sclerosis: Exosomes originating from the astrocytes of ALS murine models [36,37], or from ALS patient iPSC-derived astrocytes [38] and motor neurons [36], have been implicated in pathogenesis [37,39,40,41], carrying misfolded proteins such as SOD1, FUS, TDP43, or toxic elements such as the dipeptide repeats (DPRs) resulting from C9orf72 expansions [36,37,40,42,43].