Deriving and identifying hepatocytes from embryonic stem cells.

The generation of hepatocytes from embryonic stem cells (ESCs) holds considerable promise for basic and applied research. However, the unequivocal identification of hepatocytes in ESC differentiation strategies has been hampered by a lack of hepatocyte-specific markers. Recent studies are beginning to address this issue with the identification of hepatocyte-specific genes and the production of hepatocytes from intermediate cell types like definitive endoderm. Assuming the successful identification of ESC-derived hepatocytes, the next challenge will be in balancing the proliferation and differentiation of these cells in order to generate usable numbers of functional hepatocytes in vitro.