Inside the hollow area of the bones is a spongy core called bone marrow. It is here, that stem cells are produced. Stem cells are immature cells that can develop into components of blood: red blood cells, which carry oxygen to the body; white blood cells which fight infection; and platelets, which help blood to clot. Acute myeloid leukemia (AML) is a cancer of blood and bone marrow. In healthy patients, stem cells produce myeloblasts, or blasts, that develop into mature types of white blood cells. In AML these blasts do not develop into mature, healthy, cells, but rather develop into immature or abnormal cells. As the number of these abnormal cells increases in the blood and bone marrow, fewer healthy, functioning blood cells and platelets are produced. There are many subtypes of AML that are categorized according to how mature the white blood cells are at the time of diagnosis and how different these cells are from normal blood cells. The cancer cells can travel in the bloodstream, or metastasize, to other organs in the body where they can begin to form additional tumors. AML is the most common type of blood cancer in adults, and it can also affect children. Symptoms consist of fatigue, fever, bleeding, and bruising. Current therapy includes chemotherapy, radiation therapy, stem cell transplantation, and drug therapy. Clinical trials involving biologic therapy may be available. Your doctor is the best source of information regarding treatment for your condition. It is important to discuss with your doctor which therapy, if any, is most appropriate for you.