While the formation of inclusions incorporating WT TDP-43 is a hallmark of sporadic ALS (4), several studies have identified the presence of misfolded, although typically unaggregated, WT SOD1 in sporadic ALS and non-SOD1 familial amyotrophic lateral sclerosis using an array of SOD1 misfolding-specific antibodies (5, 6, 7, 8, 9, 37, 38). Here, SOD1 is linked to familial amyotrophic lateral sclerosis.