MAPT and Alzheimer disease: In recent decades, several in vivo biomarkers able to quantify the main AD-related changes present in the brain (Aβ-amyloid (Aβ) plaques, neurofibrillary tangles composed of hyperphosphorylated tau, neurodegeneration and vascular changes) have been developed, including fluids (cerebrospinal fluid (CSF), plasma), imaging (magnetic resonance, positron emission tomography (PET)) and genomic tools.