OGG1 and Alzheimer disease: Moreover, significantly worse efficiency of OGG1 dependent BER mechanism (lowest ratio of 8-oxo2dG/OGG1) was observed in AD patients before the treatment (0.8072, p<0.05 vs. UC and RC), in the first five years of AD (1.379, p<0.01 vs. UC and p<0.001 vs. RC), in patients with mild and moderate dementia (0.7233, p<0.001 vs. UC and RC, and 1.846, p<0.05 vs. RC; Supplementary Tables 1-3).