MAPT and Alzheimer disease: A recent MEDLINE search for the most common biomarkers of AD (Aβ, tau, MRI, PIB-PET, FDG-PET) performed by Noel-Storr et al (181) resulted in 19 104 published references, 1032 of which were cross-sectional studies, 500 longitudinal studies, while the rest of the publications was not relevant.