MAPT and Alzheimer disease: AD is the most common form of dementia, and its prevalenceis expected to increase from 50 million people in 2010 to 113 millionby 2050 worldwide.1,2 AD is often divided into threestages: (1) preclinical stage characterized by normal cognitive ability,(2) prodromal stage characterized by mild cognitive impairment (MCI),and (3) dementia stage.1,3 Current diagnosis relies on clinicalsymptoms and pathological alterations indicated by biomarkers, suchas reduced amyloid-β1–42 (Aβ1–42) or increased p-Tau and t-Tau concentrations in cerebrospinal fluid(CSF).