MAPT and Alzheimer disease: • Hyperphosphorylated 4-repeat tau protein within the cell bodies in the form of swollen, achromatic (ballooned) neurons, and in glial cells as astrocytic plaques. Gross neuronal loss is seen in an asymmetric fashion in the frontoparietal lobe (15) • The diagnosis of CBS is clinical in the absence of histopathological confirmation, and may include other pathologies in addition to the histopathologically-confirmed CBD, such as those of AD, PSP, Lewy bodies, and other tau-positive and tau-negative (primarily TDP-43 positive) forms of frontotemporal lobar degeneration (6)