Since the discovery of Aβ and tau, the development of diagnostic and therapeutic strategies for Alzheimer’s disease (AD) has initially focused on Aβ (1–3), but tau has received more attention in recent years, in part because of the failure of several Aβ-targeting treatments in clinical trials (1, 4–6) and a stronger association between tau pathology and cognitive decline (1, 3). This evidence concerns the gene MAPT and Alzheimer disease.