Primary tauopathies can be further classified as 3-Repeat (3R; PiD), 4-Repeat (4R; PSP, CBD), and 3R+4R (PART) based on the predominance of the tau isoform present in the cytoplasmic inclusions characterizing each disease (Figure 2) [13]. The gene discussed is MAPT; the disease is supranuclear palsy, progressive, 1.