MAPT and Alzheimer disease: Post-mortem neuropathological studies are less feasible among centenarian offspring than their centenarian parents because they are often still many years from death, therefore, biomarkers of AD pathology should be obtained by assays of cerebrospinal fluid at a minimum or ideally, in vivo imaging including magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and positron emission tomography (PET) for amyloid and tau proteins.