In vivo, the pathological processes associated with AD can be measured  by biomarkers of aggregated Aβ, such as positron emission tomography (PET) Aβ‐PET or cerebrospinal fluid (CSF) Aβ42/Aβ40 protein ratios, and biomarkers of neurofibrillary tangles, such as tau‐PET and plasma tau.15 Here, MAPT is linked to Alzheimer disease.