HNF4A and type 2 diabetes mellitus: HNF4α is most highly expressed in the liver, kidney, intestine, and pancreas, where its dysregulation is strongly linked to type 2 diabetes, due to its downregulation of the INS promoter, via binding to an alternative promoter.42 By exploiting that relationship, using an INS reporter in a high-throughput compound screen,19 an HNF4α inhibitor, BI6015, was discovered; BI6015 was also selectively cytotoxic to numerous cancer (but not normal) cells.