MAPT and Alzheimer disease: Indeed, a robust correlation between biochemical measures of AT-8 phospho-tau and total Aβ measures was observed when considered as a single cohort (non-AD + AD cases, Braak stage 0-VI) in the GM (r = 0.78, p < 0.0001, Fig. 1d.i) and in the WM (r = 0.75, p < 0.0001, Fig. 1e.i).