MAPT and Brain atrophy: The biomarker diagnosis of AD is summarized as the ATN framework, i.e., “Aβ”, “Tau” and “neurodegeneration”, including A: Aβ-PET (Positron Emission Computed Tomography) of the brain, Aβ42 in body fluids or Aβ40/Aβ42, T: Tau-PET, P-Tau181 or P-Tau217, N: FDG(Fluorodeoxyglucose)-PET or MRI (showing brain atrophy and distinguishing it from other diseases such as cerebral hemorrhage), Total Tau, Neurofilament light (NfL), etc. (68).