IAPP and pancreatic insulinoma: IAPP exposure in rat insulinoma, RINm5F, cells and human islet β-cells [136,137] has been shown to up-regulate pro-apoptotic genes—c-fos, fosB, c-jun, and junB [138]—in a time and concentration-dependent manner, as well as to increase the expression of apoptotic markers p53 and p21WAFI/CIPI [139].