OUTLINE: Patients have bone marrow samples collected during the course of therapy on the CCG 2961 acute myeloid leukemia treatment protocol. These samples are collected: 1. At the time of diagnosis 2. At the end of induction (within a week of day 35) 3. At the end of consolidation (before bone marrow transplant or Capizzi 2) 4. Before and after interleukin-2 (IL-2) therapy, if applicable 5. At the end of therapy (after transplant with evidence of engraftment for autologous bone marrow transplant patients; after course 2 of intensification for chemotherapy patients; and after IL-2 day 21 for IL-2 patients) 6. At relapse, if applicable. The presence of minimal residual disease in bone marrow is assessed using multidimensional flow cytometry and PCR.