MAPT and Alzheimer disease: Compared with previously established HEK293-based tau seeding reporter cell lines, our HA-tau297–391 biosensors outperformed 0N4R tau P301S-Venus cells (19) in detecting AD-derived seeds for all the titrated amounts, whereas the sensitivity was similar to that of the most widely used tau RD P301S FRET seeding biosensor system (18) (Fig. 2C).