The core AD biomarkers can be classified into two groups: biomarkers of Aβ peptide deposition, including decreased levels of Aβ42 in cerebrospinal fluid (CSF) and amyloid positivity using positron emission tomography (PET), and biomarkers of neuronal injury and degeneration, including elevated levels of phospho-Tau181 (pTau181) and total Tau (tTau) in CSF, decreased fluorodeoxyglucose F18 (FDG) uptake on PET, and disproportionate atrophy on structural magnetic resonance imaging [9]. This evidence concerns the gene MAPT and Alzheimer disease.