Family of hematopoietic growth factors that regulate the production of myeloid cells. Glycoprotein hormones that stimulate cell proliferation, survival, differentiation commitment, and end-cell functional activity; important to the inflammatory and immune response. Cell types capable of producing one or more CSFs include monocytes, T-lymphocytes, endothelial cells, fibroblasts and skin epithelial cells. Originally identified by their ability to stimulate the in vitro growth of hematopoietic progenitor cells into colonies in semisolid media: D. H. Pluznick, L. Sachs, J. Cell. Comp. Physiol. 66, 319 (1965); T. R. Bradley, D. Metcalf, Aust. J. Exp. Biol. Med. Sci. 44, 287 (1966). Distinguished by the type(s) of progeny cells which result from stimulation by the specific factor, CSFs include: granulocyte-CSF (G-CSF), granulocyte-macrophage CSF (GM-CSF), macrophage-CSF (M-CSF) and multi-CSF or interleukin-3 (IL-3), q.q.v. G-CSF and M-CSF are thought to act on late progenitor cells already committed to their respective lineages. GM-CSF and IL-3 act on earlier, pluripotential progenitors. Potential clinical applications include the reduction of myelosuppression during cancer chemotherapy; augmentation of host defense in infection; and differentiation induction in hematologic malignancies. Reviews: D. Metcalf, Science 229, 16-22 (1985); S. C. Clark, R. Kamen, ibid. 236, 1229-1237 (1987); J. D. Griffin, Oncology 2, 15-21 (1988). Role in infectious disease: R. M. Rose, Semin. Oncol. 19, 415-421 (1992). Reviews of biological effects and clinical potential: J. L. Gabrilove, Cancer Chemother. Biol. Response Modif. 10, 492-506 (1988); J. E. Groopman et al., N. Engl. J. Med. 321, 1449-1459 (1989); J. A. Hamilton, Immunol. Today 14, 18-24 (1993).