ADARB2 and Alzheimer disease: Reduced Representation Bisulfite Sequencing of monozygotic and dizygotic twin pairs to examine whether epigenetic profile differences associated with AD could be detected in the blood of participants sharing similar genetic risk profiles shows twin pairs contain epigenomic differences in AD pathology associated genes such as ADARB2, including differentially methylated sites in hippocampal cells rather than just blood cells (Konki et al., 2018).