Currently, the following biomarkers have sufficient accuracy to be diagnostic of AD: amyloid PET; CSF Aβ 42/40; CSF p-tau 181/Aβ 42, CSF t-tau/Aβ 42; or “accurate” plasma assays, where “accurate” is interpreted as accuracy that is equivalent to endorsed CSF assays in discovering abnormal amyloid PET in the intended-use population [12]. Here, MAPT is linked to Alzheimer disease.