MAPT and supranuclear palsy, progressive, 1: All tauopathies are characterized by the presence of aggregates of abnormally phosphorylated tau protein, although the isoforms that aggregate vary.7 Both hyperphosphorylation and accumulation of 4R tau protein in neurons and glia, in basal ganglia and in the brain stem, are characteristic features of PSP.8 In PSP, the abnormal phosphorylation of tau triggers its detachment from MTs, mislocalization from the axon to dendrites and accumulation of still‐soluble “oligomers.”9