Fourth, in the post-mortem part of the study, tau pathology was assessed in only one hemisphere per individual, which may not fully capture lateralized pathology, especially in syndromes like lvPPA-AD and CBS-AD where asymmetric neuropathologic distributions are well documented.36,38 Fifth, the two sites that provided post-mortem tau data employed different methodologies. This evidence concerns the gene MAPT and Alzheimer disease.