MAPT and Alzheimer disease: Using two HEK293 reporter cell lines previously established to investigate TDP-43 and Tau seeding (De Rossi et al, 2021; Holmes et al, 2014), we found that seeding-competent Tau and TDP-43 species are present in brains of AD+ patients (Fig. 7), even without TDP-43/phosphoTDP-43 being detectable by Western blot (Fig. EV4).