The subject of this volume is to review chemical agents which affect blood and blood-forming organs. Significant ad- vances made over the past several years in the purification of several hematopoietic growth factors, such as erythro- poietin and colony stimulating factor; the availability of several other growth factors, such as the interleukins which are important in regulating the production of red blood cells, leukocytes, megakaryocytes and platelets are discus- sed. Numerous toxic chemical substances are being produced in our environment which people are exposed todaily causing a suppression of erythropoiesis, myelopoiesis and megakaryo- cytopoiesis. Attempts to evaluate both the therapeutic role of some of the newer growth factors, such as erythropoietin in the anemia of end stage disease, as well as colony stimu- lating factors in somehematopoietic abnormalities are also covered in this volume. In addition, numerous chemical fac- tors in our environment which suppress major hematopoietic lineages stimulated by erythropoietin, macrophage colony stimulating factor, granulocyte colony stimulating factor, interleukin 1-alpha, 1-beta, 2,3,4,5,6, and 7 are also in- cluded. In addition, chapters on the use of erythropoietin in the treatment of anemia of end stage renal disease can provide the practicing hematologist and nephrologist with updated information on the use of erythropoietin for this disease. The book includes chapters on the fundamental con- trol of hematopoiesis and other mechanisms of action of erythropoietin, and finally an up-to-date overview of the chemotherapy of leukemia. This book will prove useful to in- vestigators in the fields of pharmacology, physiology, nephrology, urology, hematology, pathology, endocrinology, biochemistry, and molecular and cell biology.