HNF1A and diabetes mellitus: The decrease in PAX6 may explain the presence of diabetes, although HNF1B does not bind PAX6 directly.36 Another model for HNF1B−/+ showed an impaired β cell differentiation and reduced proliferation of the foregut and pancreatic progenitors, which addressed the underlying cause for pancreatic hypoplasia.37 The HNF1B−/+ pancreatic progenitors, compared to their isogenic controls, also showed decreased expression of HNF1A and the Hippo signaling regulator, ROBO2, the downstream targets of HNF1B.37