MAPT and Alzheimer disease: Because acetylation of Lys-321 also inhibits phosphorylation on Ser-324, and the aberrant accumulation of pSer-324–positive tau is detected in APP and tau animal models, as well as patients with AD, augmenting acetylation of Lys-321 would be anticipated to prevent both tau aggregation and abnormal phosphorylation of Ser-324.