A 2016 systematic review by Wen et al. described studies reporting higher methylation levels of several genes (observed in peripheral blood cells or brain tissue of AD patients) including OPRK1, BDNF, UQCRC1, HTERT, TREM2, TBX2AR, SORBS3, SPTBN4, and CREB promotors and the synaptophysin gene [30]. The gene discussed is UQCRC1; the disease is Alzheimer disease.