In relapsed or resistant acute myeloid leukemia (a type of blood cancer where immature blood cells are increased, blocking normal blood cell production), different types of chemotherapy are used for treatment. Patients responded to all the chemotherapies in similar ways, but most of the responses did not last long if further stem cell transplantation was not done. Gleevec is believed to work by interfering with the abnormal protein by blocking it from telling the body to keep making more white blood cells that are abnormal.