Progressive supranuclear palsy (PSP) is a neurodegenerative disorder caused by the accumulation of four-repeat (4R) tau protein in neuronal and glial cells.1 Neuronal lesions include globose-shaped neurofibrillary tangles located in the cytoplasm and dense neuropil threads involving neuronal processes. The gene discussed is MAPT; the disease is Classical progressive supranuclear palsy.