MAPT and supranuclear palsy, progressive, 1: Interestingly, it has been reported that LNT is hierarchically closer to PSP than CBD in terms of tau filaments3 and CNS histopathology.14 Furthermore, it may also be necessary to investigate the relationship between PNS-tau and one of the special tau isoforms that are abundantly expressed in the PNS, the so-called ‘big tau’.38-40 Interestingly, big tau has been reported as 4R-tau.41,42