Enhanced senescence has been found in AD and DS brains [15], and it has been proposed to play an important role in the onset and aggravation of AD neuropathology, including Aβ deposition [267], tau phosphorylation [268], increased release of proinflammatory cytokines [269,270] (see Section 7), and alterations in mitochondrial function and OS [176]. This evidence concerns the gene MAPT and Alzheimer disease.