Abnormalities in the levels and localizations of Dnmt1, Dnmt3a, and 5mC have been found in human ALS spinal cord and motor cortex (Chestnut et al., 2011), and mitochondrial abnormalities in skeletal muscle, liver, spinal motor neurons, and motor cortex have been reported in human ALS (Sasaki and Iwata, 1999; Menzies et al., 2002). Here, DNMT1 is linked to amyotrophic lateral sclerosis.