To tell whether the transplant has worked or "engrafted", we will take samples of bone marrow (bone marrow aspirate). We will do this 3 weeks after the transplant to make sure the new cells are beginning to grow. We will take another marrow sample at 3 months after the transplant. We want to make sure the new cells are still growing. This test will take about 30 to 45 minutes. Because this test is painful, the patient will be given pain medicine before, during, and after the test.