Moreover, tau pathology in the AD brain originates in the entorhinal cortex and hippocampus, eventually spreading throughout the forebrain, but in PSP tau pathology is restricted to the basal ganglia, brainstem, substantia nigra, and subthalamic nucleus [78,79], and in CBD it is restricted to the cerebral cortex [79]. The gene discussed is MAPT; the disease is Alzheimer disease.