CBD is defined neuropathologically by the abnormal deposition of aggregated 4-repeat tau protein isoforms in neurons and glial cells, as outlined by Dickson et al. 2 In all, 24%–57% patients with CBD (at autopsy) had been correctly diagnosed in their lifetime.9–11 Conversely, many patients who were diagnosed with CBS or clinical CBD had another diagnosis by pathology, most commonly AD and frontotemporal dementia.4, 6. Here, MAPT is linked to Alzheimer disease.