MAPT and Alzheimer disease: In the present study, we unilaterally injected AD P-tau into the hippocampus of 9–11-month-old Tg/hTau mice and found for the first time that in addition to the induction of tau aggregation/pathology, AD P-tau led to site-specific hyperphosphorylation and SDS- and reducing agent-resistant and AD-like high-molecular weight tau in vivo 10 weeks post injection.