Erythropoietin has become a hormone urgently needed by the tens of thousands of patients with chronic renal disease. Its availability would ensure that the hemoglobin and oxygen carrying capacity could be maintained without the use of transfusions. This would eliminate transfusion reactions, but more importantly, decrease sensitization to tissue antigen and facilitate potential future transplantations. The studies of the biogenesis of erythropoietin are primarily aimed at accomplishing mass production or mass isolation of erythropoietin for this use. These studies would also help in our understanding of the dual effect of uremia and renal damage on erythropoietin production and of the pathogenesis of anemia of infection, inflammation and cancer. The stem cell studies are aimed at providing a better understanding of the action of erythropoietin on the bone marrow. This understanding will hopefully clarify the pathogenesis of such diseases as aplastic anemia, polycythemia vera and the myeloproliferative syndromes and help us designing better modes of management.