H1-4 and Alzheimer disease: The post-translational modifications of histones, such as acetylation and deacetylation, have been increasingly recognized as critical factors affecting gene activation and silencing in the brain of individuals with neurodegenerative disorders.79, 80, 81, 82, 83 Aside from its post-translational modifications, the expression levels of histones are also important for cell cycle control.84 Here, we show that the expression of HIST1H1E was increased in the AD Hp, whereas the expression of HIST1H1D was increased in the AD pCx but decreased in the AD Cb.