Liver cell transplantation is a procedure that shows great promise for the treatment of many diseases now treated definitively only with whole organ transplantation. Organ transplantation involves major surgery, requires the use of scarse donor organs, is expensive and requires life-long immunosuppression. Potential advantages of cell transplantation include a simpler, safer, less costly procedure that takes advantage of currently discarded liver segments, and could use stem or in-vitro expanded cells.