Although CSF AD biomarkers are well established, plasma biomarkers have only been described recently and are undergoing standardization.4,8,11 Blood-based biomarkers have the major advantage of being more accessible than CSF or PET imaging.4 Within AD itself, plasma biomarkers of AD pathology are strongly correlated with CSF biomarkers and with amyloid/tau PET imaging.9,11,56,57 However, plasma AD markers in DLB have been less well studied. The gene discussed is MAPT; the disease is Alzheimer disease.