MAPT and Alzheimer disease: However, the quantification of total MSUT2 and tau pathology showed that neuronal MSUT2 levels were significantly elevated in AD and corticobasal degeneration (CBD) cases (Fig. 1d, e), with a non-significant trend toward increase in PSP cases (Fig. 1f) that showed higher variability and a lower level of tau pathology than AD or CBD cases.