Acute myeloblastic leukemia (AML) is a disorder characterized by excessive proliferation and aberrant differentiation of immature myeloid cells. Leukemic cells are maintained by a small population, leukemic blast progenitors, with self-renewal capacity. The cause of AML and the mechanisms whereby leukemic cell population expand escaping from normal hemopoietic regulation still remain to be determined. The response to growth factors of leukemic blast progenitors and possible mechanisms of growth factor involvement in the leukemic process including the oncogene relationship are reviewed.