Kobayashi et al. (2016), Shinagawa et al. (2016), and Chen et al. (2021) have successively confirmed that the level of NCAPH2 methylation in peripheral blood of AD patients is lower than that of normal people and NCAPH2 hypomethylation is significantly positively associated with the hippocampal volume in patients. This evidence concerns the gene NCAPH2 and Alzheimer disease.