ABSTRACT
Hepatic oval “stem” cells have been studied in rodents since the mid-1950s when they were first described by E. Farber. 1 Hepatic oval “stem” cells have been shown to be a cell type capable of developing into hepatocytes or bile duct epithelial cells. 2 , 3 Numerous in vivo and in vitro studies have shown a central role of oval cells in liver biology and carcinogenesis. 4-7 In addition to the effects seen in the liver, oval cells (or cells very similar to oval cells) have been seen in the architecture of the regenerating pancreas after injury. 8 , 9 While there is a specific function for this cell population in the liver, the mechanism(s) by which oval cells activate, proliferate and differentiate are poorly understood. In spite of four decades of research and over 300 publications on hepatic oval “stem” cells, their ontogeny remains unidentified.
