APP and synucleinopathy: Since the pioneering work of Schenk et al. [58], who vaccinated PDAPP transgenic mice overexpressing mutant human APP with pre-aggregated Aβ(1-42) as a putative active immunotherapeutic strategy against AD, several other vaccines have been described; these vaccines have been mainly based on the most popular scenarios concerning the pathogenesis of neurodegeneration, i.e., amyloidosis and tauopathies [126] as well as synucleinopathies [46].