MAPT and tauopathy: We documented propagation of S1p-induced tauopathy (CP13 staining) in these cultures (Fig. 7c, supplemental Fig. 7c–d) and then used immunoblotting to quantify seeded tau using the pTau antibody CP13; these studies demonstrated that TIA1 knock down reduced levels of pTau induced by S1p seeding (Fig. 7d–f, supplemental Fig. 7c–d).