Recombinant human colony‐stimulating factors (CSFs) have potential for wide use in the areas of oncology and infectious disease. Granulocyte CSF and granulocyte‐macrophage CSF currently are approved for use in the treatment of neutropenia associated with standard‐dose cancer chemotherapy and bone marrow transplantation, respectively. Other settings in which these agents have shown promise are dose‐intensive chemotherapy, enhancement of progenitor cell support, primary and acquired neutropenias, myelodysplasia, aplastic anemia, and cytopenias associated with human immunodeficiency virus infection or myelosuppressive therapies for such infection or related conditions. Clinical findings in these areas are encouraging, and potential exists for additional applications of t