MAPT and Alzheimer disease: There are various descriptive hypotheses regarding the causes of sporadic AD, including the cholinergic hypothesis [13], amyloid hypothesis [14,15,16], tau propagation hypothesis [17,18], mitochondrial cascade hypothesis [19,20], calcium homeostasis hypothesis [21,22], inflammatory hypothesis [23,24,25], neurovascular hypothesis [26], metal ion hypothesis [27,28,29], and lymphatic system hypothesis [30,31].