MAPT and Alzheimer disease: Further investigations arerequired to determine the precise biochemical pathways responsible for thisinteraction, the relative contributions of different processes (includingAβ-associated Ser129 phosphorylation of α-syn and α-syn-associatedphosphorylation of tau) on the development of combined AD and Lewy bodypathology and the progression of neurodegeneration, and also the possibleinfluence of Aβ on other potential sites of α-syn phosphorylation.