In particular, hepatic nuclear factor 1β (HNF1B), associated with MODY5 (Horikawa et al., 1997), plays an important role in the normal development of the kidney, liver, pancreas, bile ducts, and urogenital tract, through tissue-specific regulation of gene expression in these organs (Barbacci et al., 1999; Coffinier et al., 1999). Here, HNF1B is linked to renal cysts and diabetes syndrome.