Earlier work has established that aggregates composed of ALS-causing SOD1 mutants can nucleate aggregation of the same soluble mutant SOD1 protein in vitro and in vivo21, 22, and that induction of HuWtSOD1 misfolding via transient transfection with mutant SOD1 triggers the propagation of HuWtSOD1 misfolding for at least 5 passages19. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.