GATA6 and diabetes mellitus: Likewise, Hnf1b, Gata4/Gata6, Pdx1 or Mnx1-deficient mice fail to develop pancreas of normal size and rather develop diabetes (Xuan et al, 2012; Flanagan et al, 2014; Stoffers et al, 1997; Haumaitre et al, 2005).