OGG1 and amyotrophic lateral sclerosis: Specifically in spinal cord motor neurons, the Ogg1 gene promoter showed significant demethylation of 1 of 4 CpG island sites in ALS cases compared to age-matched control (Fig. 8e), but no significant changes in Ogg1 promoter methylation were seen in ALS dorsal horn Rexed laminae II, III, and IV (Fig. 8f).