MAPT and early-onset autosomal dominant Alzheimer disease: Alzheimer’s disease (AD) is the most common form of dementia, characterized by extracellular amyloid-beta (Aβ) plaques and intracellular tau protein tangles, which are believed to be central to its pathology.[1–3] Recent studies have reported an interaction between Aβ and tau proteins in the pathogenesis of AD, contributing to disease progression.[4–9] For instance, Lee et al.[7] revealed that Aβ-tau interactions are associated with the propagation of tau.