The conversion of one differentiated cell-type into another, challenges our long-held view of differentiated cells being in a fixed terminal stage of differentiation, incapable of reversal or change. Such conversions are most favourable between developmentally related cell-types such as hepatocytes from the liver and cells of the pancreas. The main drawback of culturing hepatocytes in vitro has been their limited life span and their rapid de-differentiation in culture. However, the de-differentiation of hepatocytes, and the progressive diminution in the transcription levels of liver-specific genes, is in fact associated with a concomitant induction of a pancreatic gene expression profile.