IAPP and type 2 diabetes mellitus: Indeed, the presence of IAPP fibrils has been identified in greater than 90% of patients with T2D.5 Because IAPP oligomers are thought to be preferentially cleared in beta cells via the autophagic pathway,2 and autophagy is impaired in T2D (as well as in type 1 diabetes),6 toxic IAPP oligomers likely accumulate in the islets of persons with T2D.