559 Although the induction of apoptosis in motor neuronal death by human mutant SOD1G93A depends on copper and the absence of zinc, chronic oral administration of zinc sulfate decreased the survival of SOD1G93A mice, indicating that zinc amplifies the SOD1G93A-mediated toxicity.560 Zinc pre-treatment also enhanced the NMDAR-mediated excitotoxicity in cultured cortical neurons derived from SOD1G93A mice.561 Additionally, zinc migration and subunit swapping in SOD1 may contribute to its neurotoxicity in ALS.562 Cytoplasmic accumulation and aggregation of SFPQ are hallmarks of ALS. Here, SOD1 is linked to amyotrophic lateral sclerosis.