Leukemia is a malignant disease which continues to play a significant role in the discovery of basic knowledge about the malignant process and about the potential for controlling these malignant diseases. This study investigates such topics as: chromosome 16; chromosome 5; the BCL-2 gene; llq23 breakpoint leukemias; the p-53 suppressor gene and oncogene; hematopoietic stem cells; cytokines; detection of minimal residual disease in acute lymphoblastic leukemia; autologous marrow transplantation; the retinoblastoma gene; allogeneic bone marrow transplant; and the chemotherapy of acute lymphoblastic leukemia.