recalls the ancient legend of Prometheus. As punishment for stealing fire and giving it to humans, the Greek god Zeus banished Prometheus to be chained to a rock on Mt. Caucasus. As part of his punishment, a bird of prey would peck out his liver daily, and every night his liver would regenerate. As mythical as the story is, the reality lies in the remarkable ability of the liver to regenerate. The explanation for the process has been of interest to investigators for more than a century (1). Regeneration is the capability of an organ to replace tissue mass after partial removal or injury. Although some other organs do demonstrate growth after injury, most undergo hypertrophic changes without significant increases in cell number. The liver is unique in its ability to undergo hyperplasia and to repopulate loss of tissue and cells. By strict definition, however, the liver does not exhibit the true regeneration demonstrated by amphibians, which can literally regrow lost tails or limbs. Rather, the liver undergoes compensatory hyperplasia aftercell loss to reestablish the optimal mass that is set in relationship to body size. Morphologically and functionally, the remaining hepatocytes do not dedifferentiate, but rather maintain an active urea cycle, albumin synthesis, and drug metabolism as well as exhibit normal polarity of membrane domains (2).