MAPT and tauopathy: The WT-Tau interaction biosensor also did not respond to seeds obtained from brain lysates of the transgenic (Tg) tauopathy mouse model carrying the P301S mutation (Figure 3B), while the K18(P301L) interaction biosensor cells showed a robust 107-fold increase in signal in the presence of brain lysates from the Tg mice compared to brain lysates from WT mice (Figure 3B).