MAPT and amyloidosis: Well-documented biomarkers of cerebral amyloid pathology are increased signals on amyloid positron emission tomography (amyloid PET) (for a recent review, see e.g. [9]), low Aβ42 concentrations in cerebrospinal fluid (CSF), a reduced CSF Aβ42/Aβ40 ratio [10, 11], and increased CSF phospho-Tau/Aβ42 and total Tau/Aβ42 ratios [12–14].