MAPT and Alzheimer disease: Noteworthy, CSF biomarkers’ predictive performance was optimal (>80%) in two clinically relevant situations, and heterogeneity was no longer significant: (1) P-tau alone had 84% sensitivity and 93% specificity for MCI cases converting to AD in ≤24 months, significantly different from 59% sensitivity (p = 0⋅01) and 71% specificity (p < 0⋅001) in studies with follow-up periods > 24 months; (2) Aβ42/p-tau ratio showed 81% sensitivity and 91% specificity in MCI patients younger than 70 years, significantly different from 66% specificity in MCI patients older than 70 years (p < 0⋅001).