MAPT and synucleinopathy: In addition to α-syn pathology, co-pathologies—specifically amyloid-beta (Aβ), phosphorylated tau (p-tau) and phosphorylated transactive DNA-binding protein 43 (pTDP-43)—are increasingly recognized as modifiers of disease phenotype and progression in synucleinopathies and other neurodegenerative disorders [19, 20].