To study the effect of 77G7 on AD O‐tau induced tau aggregation in vivo, we bilaterally injected 0.25 μg AD O‐tau or a mixture of 0.25 μg AD O‐tau with 1.5 μg 77G7 or with mIgG into the hippocampi of 10‐month‐old 3xTg‐AD mice, a widely used AD mouse model.45 Here, MAPT is linked to Alzheimer disease.