Pathogenic Aβs trigger aberrant epigenetic modifications, such as acetylation of histones, DNA methylation status, and expression of non-coding RNA, contributing to the overexpression of AD-associated genes such as APP, PSEN1, PSEN2, and BACE, or to the decreased expression of Aβ-degrading proteases. This evidence concerns the gene PSEN2 and Alzheimer disease.