SOD1 and amyotrophic lateral sclerosis: Increased iron levels were reported in spinal cord MN in two ALS SOD1-mouse models, SOD1 G93A (Lee et al., 2015) and SOD1 G37R (Jeong et al., 2009), by staining ventral MN with Perl’s (Fe3+) and Turnbull’s (Fe2+) reactants.