Consequently, if not returned to homeostasis, continual neuronal stress will promote and exacerbate diverse neuropathologies (e.g. phospho-tau and higher levels of Aβ42) in a vicious cycle that ultimately progresses to neurodegeneration and associated cognitive and neuropsychiatric symptoms typical of AD, as outlined in the current hypothetical model of AD biomarkers evolution [12]. This evidence concerns the gene MAPT and Alzheimer disease.