SOD1 and amyotrophic lateral sclerosis: In addition, mitochondrial vacuolization and the levels of protein SNO were reduced in the spinal cords of mutant SOD1 transgenic mice, suggesting that ALS-associated mutations in SOD1 enhance its denitrosylase activity and reduces the SNO of mitochondrial proteins, leading to mitochondrial dysfunction, and, ultimately, ALS-related pathology.