MAPT and supranuclear palsy, progressive, 1: In GGT cases, a fibrous core structure consisting of G272-R379 in 4R tau, akin to the PSP fold, was identified, and while only protofilament-type tau filaments were found in PSP cases, multiple structures consisting of two protofilaments packed at different interfaces were found in type I and type II cases in the three types of GGT (Table 1) [266].