Hepatocyte nuclear factor. Molecule model of the transcription factor hepatocyte nuclear factor 1alpha (HNF-1a). Transcription factors are proteins that bind to specific sequences of DNA and control the transcription (transfer) of genetic information from DNA to RNA (ribonucleic acid). HNF-1a is predominantly expressed in the liver where it is involved in regulating insulin expression and glucose metabolism. Mutations in this protein cause a form of type II diabetes.