MAPT and neurodegenerative disease: Indeed, in this context, it should be noted that propagation and spread of assemblies of amyloid-β, tau and α-synuclein in animal models of other neurodegenerative diseases rarely result in lethal neurodegeneration, suggesting that the basic architecture of mammalian prions may be unique and central to their lethality (Collinge, 2016; Terry et al., 2019).