Archived CSF confirmed the presence of anti-IgLON5 antibodies and the neuropathological examination showed an extensive brainstem tauopathy, as expected for the anti-IgLON5 disease-related tauopathy, which, however, formally fulfilled the neuropathological criteria of a PSP phenotype [8]. Here, IGLON5 is linked to supranuclear palsy, progressive, 1.