Interestingly, however, we observed a significant negative correlation between 8-oxodG levels and OGG1 activity only in the control group (R2 = 0.6356, p = 0.0102) but not in PD (R2 = 0.4797, p = 0.0864) (Supplementary Fig. 1c). The gene discussed is OGG1; the disease is Parkinson disease.