MAPT and Alzheimer disease: Tests performed for the AD diagnosis are generally invasive, such as those requiring lumbar puncture for cerebrospinal fluid (CFS) collection to measure the amyloid-β, tau protein (T-tau) and phosphorized tau protein (P-tau) levels; or are expensive and time-consuming, such as structural neuroimaging techniques (MRI magnetic resonance imaging and computed tomography), positron emission (PET) imaging of cerebral amyloid, or inflamed proteins and neuropsychological tests9,10.