MAPT and Alzheimer disease: Currently available biomarkers for AD make it possible to detect the peptide amyloidβ (Aβ-42) and tau protein, which show correlation with the pathologyof AD.6 Alteration in the peptideAβ-42, albeit a decrease in its concentration in spinal fluid or theidentification of deposits of the peptide in cerebral tissues can be detected by newmolecular neuroimaging methods of positron emission tomography (PET).