Isolated liver progenitor stem cells and cell populations of isolated liver progenitor stem cells are disclosed. The progenitor stem cells originate from adult liver, especially human adult liver. The isolated progenitor stem cells have uses in medicine, hepatology, inborn errors of liver metabolism transplantation, infectious diseases and liver failure. Methods of isolating these cells and their culture is described. The isolated cells are characterized before and after differentiation. Their use for transplantation and as animal models of human disease, toxicology and pharmacology is disclosed.
