MAPT and Classical progressive supranuclear palsy: Amyloid beta (Aβ) peptide and tau protein in AD, tau protein in primary tauopathies (including progressive supranuclear palsy [PSP]) and α-synuclein in PD and other synucleinopathies, are some of the main proteins implicated in this aggregative mechanism at the origin of the neurodegenerative processes.