Abstract: The current invention is related to a method for the production of a human monoclonal antibody from a immunodeficient non-human animal, said method comprising contacting a new borne immunodeficient non-human animal with a human fetal liver stem cell (FL cell) to generate an immune transplanted non-human animal (reconstituted animal), subsequently contacting said reconstituted animal with a antigen, collecting from said reconstituted animal a human cell producing human antibody against said antigen, and isolating said antibody from said antibody producing cell.