Human Granulocyte-Colony-StimulatingFactor (G-CSF) is 20 kD glycoprotein containing internal disulfide bonds. Itinduces the survival, proliferation, and differentiation of neutrophilicgranulocyte precursor cells and it functionally activates mature bloodneutrophils. Among the family of colony-stimulating factors, G-CSF is the mostpotent inducer of terminal differentiation to granulocytes and macrophages ofleukemic myeloid cell lines. The synthesis of G-CSF can be induced by bacterialendotoxins, TNF, Interleukin-1, and GM-CSF. Prostaglandin E2 inhibits thesynthesis of G-CSF. In epithelial, endothelial, and fibroblastic cellssecretion of G-CSF is induced by Interleukin-17.Recombinant Human GranulocyteColony-Stimulating Factor(rhG-CSF) produced in E. coli is a singlenon-glycosylated polypeptide chain containing 175 amino acids with a molecularmass of 18.8 kD.