We therefore evaluated Dnmt3a and mtDNA methylation in several tg mouse models of ALS expressing mutant and wildtype hSOD1 either non-conditionally with global tissue expression (Gurney et al., 1994; Martin et al., 2007, 2009; Gertz et al., 2012) or conditionally with muscle-restricted expression (Wong and Martin, 2010). This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.