It has been recently demonstrated that elevated levels of thiobarbituric acid-reactive substance (TBARS) as well as oxidative DNA damage, measured by 8-OxoG, and reduced levels of the protein responsible for removing damaged DNA, 8-OxoG DNA glycosylase 1 (OGG1), were detected in the brains of patients with AD [7,37]. Here, OGG1 is linked to Alzheimer disease.