Liver development: A paradigm for hepatobiliary disease in later life

The hepatobiliary system develops from a thickening of endothelial cells in the ventral part of the foregut. These cells form the hepatic and cystic d iverticula, which undergo a series of events including cellular proliferati on, migration, and differentiation to form the liver parenchyma and the duc tular system. Studies in the developing liver suggest that surrounding meso derm and ectoderm participate in the hepatic specification of the endoderm, and that transcription factors such as cJun, retinoblastoma gene, and nucl ear factor kappa B are important regulators of liver embryogenesis. A revie w of the recent data on the role of transcription factors, growth factors, and cytokines in liver development provides insight on the ability of the l iver to respond to injury and on the molecular basis of hepatobiliary disea ses.