MAPT and Alzheimer disease: Although the ultimate confirmation of AD pathology is by autopsy examination of brain tissue for extracellular amyloid plaques made of amyloid-beta (Aβ) peptides and intraneuronal neurofibrillary tangles (NFTs) containing phosphorylated tau (p-tau) forms [2, 3], in vivo diagnosis is presently achieved by using either cerebrospinal fluid (CSF) or neuroimaging biomarkers.