To address whether misfolded apo-SOD1S-S could be transmissible between cells and induce intracellular propagation of hSOD1 misfolding in recipient cells, our first approach was to use conditioned medium from the NSC-34 cells expressing GFP-tagged hSOD1WT or the ALS-causing hSOD1 mutants. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.