IAPP and type 2 diabetes mellitus: Nevertheless, an important role for hIAPP in T2DM is underscored by the observations that a high prevalence of hIAPP aggregates is found in humans with T2DM5,11,26 and that for species whose IAPP cannot form fibrils it has been reported that they do not develop T2DM characterized by islet amyloid deposits27–29.