MAPT and Parkinson disease: Larger in vivo cohorts including the European DLB Consortium (E-DLB), Mayo Clinic Cohort, and Amsterdam Dementia Cohort have shown that AD biomarkers, either CSF (most commonly CSF tau/Aβ42 ratio) or PET markers, are increased in DLB over PD and PDD and correlate with DLB dementia, progression, and survival.