MAPT and type 2 diabetes mellitus: For instance, Aβ is a potent seed for the aggregation of human islet amyloid polypeptide (hIAPP) involved in type II diabetes (O’Nuallain et al., 2004; Oskarsson et al., 2015); Aβ and prion protein PrPSc cross-seed each other and accelerate neuropathology (Morales et al., 2010); and both α-synuclein and Aβ co-aggregate with tau and enhance tau pathology in vivo (Guo et al., 2013; Vasconcelos et al., 2016).