MAPT and Alzheimer disease: Remarkably, the spreading/propagation of tau neuropathology into the Aβ plaque-bearing cerebral cortex is associated with the transition from the preclinical (asymptomatic) to the clinical (symptomatic) stage of Alzheimer’s disease (Delacourte et al., 1999; Wang et al., 2016; Pontecorvo et al., 2017).