The plasma amyloid beta (Aβ) 42/40 ratio and phosphorylated tau (p‐tau) are disease‐specific biomarkers of Aβ and tau pathologies and have been recommended in recent Alzheimer's Association criteria for diagnosing AD when shown to have at least 90% accuracy in comparison to amyloid PET or CSF assays.15 Here, MAPT is linked to Alzheimer disease.