MAPT and Alzheimer disease: Tau phosphorylation at Thr231, together with tau phosphorylations at Thr181 and Thr217 are considered early biomarkers of AD, that raise their levels in CSF of AD patients, increasing early in the Alzheimer’s continuum, when only subtle changes in Aβ pathology are detected (Luna-Munoz et al., 2007; Suarez-Calvet et al., 2020).