SOD1 and amyotrophic lateral sclerosis: Moreover, the increase of cytosolic oxidative stress caused either by the deletion of SOD1 (Sod1−/− mice) or by introduction of mutations of SOD1, (e.g., the SOD1G93A amyotrophic lateral sclerosis mutant mouse model) increases ROS levels, causing muscle atrophy and weakness in mice which are phenotypically similar to muscle changes observed in older animals [54,58].