The similarity in tau burden across some subcortical and brainstem regions may not be surprising; however, since patients with PSP-SL often develop the classic features of PSP-RS over time, most commonly meeting clinical criteria for PSP 6–7 years after onset.17 In this cohort, postural instability/falls, as well as supranuclear gaze palsy, developed in 44%, and akinesia developed in 88% of the PSP-SL patients by the last clinical evaluation. The gene discussed is MAPT; the disease is supranuclear palsy, progressive, 1.