I. Hematopoietic Regulators -- 1. Role of T-Lymphocyte Colony Enhancing Factor, TLCEF, in the Induction of CFU-TL -- 2. Thymic Hormones in Thymus Recovery from Radiation Injury -- 3. Early Biochemical Steps in Colony Stimulating Factor (CSF) Generation are Induced by Synergy between Phorbol Esters and Calcium Ionophores -- 4. Dependence of CFU-S Proliferation on the CFU-S Population -- 5. Interaction of Interleukin 3 with Pluripotent Hematopoietic Stem Cells -- 6. In Vivo Effects of Urinary Extracts of Patients with Aplastic Anemia on Rat Platelet Production and Megakaryocyte Progenitors in Murine Spleen and Bone Marrow -- 7. Inhibitor(s) of Biologically Active Erythropoietin in Concentrated Human Sera -- II. Hematopoietic Microenvironment -- 8. Establishment of Bone Marrow Stromal Cell Cultures and Permanent Clonal Stromal Cell Lines from Osteopetrotic (mi/mi) and Steel Mutant (Sl/Sld Mice: Studies of Bone Resorption by Engrafted Hemopoietic Stem Cells In Vitro -- 9. Monoclonal Antibodies Identify Specific Determinants on Reticular Cells in Murine Embryonic and Adult Hemopoietic Stroma -- 10. Stromal Cell Lines from Mouse Bone Marrow: A Model System for the Study of the Hemopoietic Microenvironment -- III. Differentiation of Normal & Leukemic Cells -- 11. Glycosphingolipids as Specific Differentiation-Markers and Differentiation-Inducers for Human Myelogenous Leukemia Cells: A Monosialyl Glycosphingolipid, Ganglioside GM3, is Highly Potent for Induction of Monocytic Differentiation of Human Myeloid and Monocytoid Cell Lines, HL-60 and U937 Cells -- 12. Properties of a T-Lymphocyte Derived Differentiation Inducing Factor (DIF) for the Myeloid Leukemic Cell Line HL-60 -- 13. Interactions of Differentiation Inducing Agents In Vitro Provide Insight into Molecular Mechanisms of Differentiation and Identify Synergistic Combinations Effective In Vivo -- IV. Leukemic Cells in Leukemogenesis -- 14. Immunoglobulin and T-Cell Receptor Gene Rearrangements in Human Acute Leukemias -- 15. Immunological and Molecular Classification of Human Leukemias -- 16. Oncogenes in Chronic Myelogenous Leukemia -- 17. Response to an Active Vitamin D3 Metabolite of Transplantable Human Myeloid Leukemic Cell Lines in Adult Nude Mice -- V. Bone Marrow Transplantation -- 18. Risk Factors for Acute Graft-vs-Host Disease in Humans -- 19. Autologous Marrow Transplantation for Malignant Lymphoma -- 20. The Influence of T-Cell Depletion by Monoclonal Antibodies on Repopulating Hemopoietic Stem Cells and Their Efficacy in Preventing GvHD in Rhesus Monkeys -- 21. Review of the Effects of Anti-T-Cell Monoclonal Antibodies on Major and Minor GvHR in the Mouse