MAPT and Alzheimer disease: Indeed, the combination of the most explored cerebro-spinal fluid (CSF) biomarkers (total tau, hyperphosphorylated tau and the β-amyloid peptide, Aβ42), neuroimaging and neuropsychological tools has been extensively investigated for a number of years and helps to differentiate AD patients from Mild Cognitive Impairment (MCI) and control subjects [1–5].