Decreased methylation levels were observed across all examined CpG sites in the MAPT gene among PD patients, with significant differences at CpGs 1, 4, 10, and 11 (p = 0.04, p = 0.014, p = 0.018, and p = 0.004, respectively) (Figure 3A). The gene discussed is MAPT; the disease is Parkinson disease.