HNF4 (Hepatocyte Nuclear Factor 4) is a nuclear receptor protein belonging to the steroid hormone receptor superfamily. HNF4 is commonly expressed in the liver and plays a critical role in liver development by establishing and maintaining hepatocyte differentiation. In human, two isoforms of HNF4 exists, alpha and gamma. HNF4 alpha is transcriptionally controlled transcription factor, which binds to DNA sites required for the transcription of alpha 1- antitrypsin, Apo CIII, transthyretin genes, and HNF1 alpha.