MAPT and tauopathy: To promote tau pathology and to examine antibody-mediated clearance of tau and prevention of its toxicity, primary tauopathy neurons (Figure 2A) and mixed tauopathy cortical cultures (Figure 3A) were treated with paired helical filament (PHF)-enriched pathological tau protein (10 μg/mL) isolated from a human tauopathy brain, with or without Asp421 antibodies (5G2 and 1G11) each at 10 μg/mL for a duration of 24, 48, 72, and 96 h.