MAPT and Alzheimer disease: As the cargoes of astrocyte‐derived EVs include misfolded proteins, such as tau and amyloid‐β (Aβ) (Chiarini et al., 2017; Eitan et al., 2016), extracellular motion of large EVs along projecting axons may underlie the propagation of Aβ/tau aggregates, which occurs through an anatomically defined pattern of connections, from the entorhinal cortex up to the hippocampal region and the neocortex in the brain of Alzheimer's disease (AD) patients (Braak & Braak, 1991).