Binding of Pdx1 to the 5'-flanking region of the IAPP gene was observed in vitro (Carty et al. 1997) and in transient transfection studies with rat cell lines (Serup et al. 1996). Reduced activity of IAPP was reported in mature murine beta cells with targeted disruption of Pdx1 (Ahlgren et al. 1998). This is consistent with the expression profile from the dominant negative suppression of Pdx1 in rat insulinoma INS1 cell line-derived stable clones (Wang et al. 2001). ChIP experiments confirmed that Pdx1 binds in vivo to the IAPP gene in murine beta cell lines (Chakrabarti et al. 2002).