MAPT and Alzheimer disease: In the present study, we found that tau phosphorylation was increased at Ser202/Thr205, Thr212, Ser214, Thr217, Ser262, and Ser422, but not at Ser199, Ser396 and Ser404, in the AD P-tau-injected hippocampus, suggesting that AD P-tau induces site-specific hyperphosphorylation of tau in vivo.