Among the family of colony-stimulating factors, Granulocyte Colony-Stimulating Factor (G-CSF) is the most potent inducer of terminal differentiation of leukemic myeloid cell lines into granulocytes and macrophages. G-CSF synthesis can be induced by bacterial endotoxins, TNF, Interleukin-1 and GM-CSF. Prostaglandin E2 inhibits G-CSF synthesis. In epithelial, endothelial, and fibroblastic cells, secretion of G-CSF is induced by Interleukin-17.