The consequences of hnf1b deficiencies are manifested by polycystic kidney disease [3], pancreas agenesis with perturbed regional specification of the gut [4], defective insulin secretion [5], defective bile system morphogenesis with liver dysfunction [6], and altered liver bud formation in combination with abnormal gut regionalization [7]. The gene discussed is HNF1B; the disease is polycystic kidney disease.