MT-ND4 and Alzheimer disease: Specifically, 10 gene regions (mt-TF, mt-RNR1, mt-TV, mt-RNR2, mt-TL1, mt-TQ, mt-TS2, mt-TE, mt-TT, and D-Loop) were found to be hypomethylated in AD patients, while 1 gene region (mt-ND4) showed hypermethylation in AD patients (Figure 4).