For AD, there are Food and Drug Administration-approved diagnostic tests for the disease pathologies, amyloid plaques and tau neurofibrillary tangles, that use positron emission tomography (PET) for direct measurement of pathology or a lumbar puncture to collect CSF for measurement of Aβ42/40 or pTau181/Aβ42 [115]. The gene discussed is MAPT; the disease is Alzheimer disease.