We have previously shown that misfolded SOD1 species are enriched in motor areas compared to other parts of the CNS and peripheral organs,71–73 as well as in iPSC-derived motor neuron cultures.74 Moreover, inclusions containing misfolded SOD1 regularly appear in motor neurons of sporadic ALS patients and patients with mutations in ALS-causing genes other than SOD1. Here, SOD1 is linked to amyotrophic lateral sclerosis.