In this review, the authors discuss the different definitions and functions of …

• Abstract
• Introduction
• Liver Stem Cell Populations
• Fetal Liver
• Adult-derived Hepatic Progenitor Cell Populations
• Cell Responses in Injury Models
• Liver Stem Cells and Transplantation
• Summary
• Acknowledgments
• References

This work was supported by NIH Grant T32-GM008450 (M.H.W.) andNIH Grant 5K08DK59302 (D.A.G.). We thank Dr. Bill Coleman forsupplying images of small hepatocyte-like progenitor cells.