GFAP and supranuclear palsy, progressive, 1: Reactive astrocytes, marked by immunoreactivity for astrocyte-specific intermediate filament, glial fibrillary acidic protein (GFAP), are associated with thorn-shaped astrocytes in ARTAG, but not with tufted astrocytes in PSP, suggesting that different astrocytic tau lesions occur through distinct mechanisms that may involve neuroinflammation [54, 84].