The current status of the approved granulocyte colony-stimulating factors (G-CSFs) and granulocyte-macrophage colony-stimulating factors (GM-CSFs) was discussed during an Educational Symposium, entitled ‘Update on Growth Factors’ at the 31st Annual Meeting of the American Society of Clinical Oncology (ASCO) held in Los Angeles, US, in May this year. In addition, data on new agents with thrombopoietic activity such as interleukin-1 (IL-1), IL-3, IL-6, IL-11, PIXY-321, SC-55464 and thrombopoietin were also presented. The reports focused on the use of these agents in providing haematopoietic support in patients with cancer who are undergoing antineoplastic chemotherapy that is likely to induce neutropenia and thrombocytopenia. Dr Langdon Miller, from the National Cancer Institute, Bethesda, US, summarises his own presentation from the session and provides an overview of the key points discussed by other speakers.