Intracellular seeded aggregation of mutant Cu,Zn-superoxide dismutase associated with amyotrophic lateral sclerosis

• Intracellular aggregation of mutant SOD1 is a major pathological change in ALS. • In vitro SOD1 fibrillar aggregates seed aggregation of endogenous SOD1 in cells. • Seeded aggregation of mutant SOD1 may describe propagation of SOD1 pathology in ALS.