HNF1ß is a master regulator with a major effect on many cystic kidney disease genes, such as PKHD1, PKD2, and UMOD, and there is evidence for a transcriptional network in PKD which is a plausible explanation of why some patients may resemble ARPKD or ADPKD patients. The gene discussed is PKHD1; the disease is autosomal dominant polycystic kidney disease.