MAPT and early-onset autosomal dominant Alzheimer disease: In line with previous preclinical in vivo and in vitro studies,16-18 recent human neuroimaging studies indicated that tau propagates throughout the brain following the functional connections from the putative sites of tau onset (i.e. tau epicenters).19,20 In Alzheimer’s disease, when Aβ plaques are widely present across the neocortex, Aβ is thought to drive tau outside of the initial site of tau deposition to gradually spread to connected regions.16,19-23