IAPP and Alzheimer disease: Linking AD and T2D from the protein aggregation perspective stems from the amyloid-like characteristics of both diseases which are marked by the excessive cell loss due to the deposition of β-amyloid (Aβ) aggregates and the islet amyloid polypeptide (IAPP) aggregates in neuronal and pancreatic tissues, respectively (Murphy and LeVine, 2010; Jurgens et al., 2011; Chiti and Dobson, 2017).