MAPT and Alzheimer disease: Based on the temporospatial progress of tau pathology in AD, Braak and Del Tredici (2011) have proposed a sequential pathway of neurofibrillary tangle propagation affecting the brainstem/locus coeruleus, transentorhinal cortex, neocortical association area and primary and secondary cortical areas and followed by the so-called “return pathway” of corticocortical projections to primary cortical fields.