Another potential biomarker of this disease could be the hypomethylation in TOMM40 (translocase of outer mitochondrial membrane 40) and APOE (apolipoprotein E) gene promoters observed in the hippocampus, cerebellum, and peripheral blood of AD patients, which correlated with increasing APOE and decreasing TOMM40 expression [61]. The gene discussed is APOE; the disease is Alzheimer disease.