Granulocyte colony-stimulating factor (G-CSF) is a hematopoietic growth factor that affects proliferation and differentiation especially of progenitors of the neutrophil and granulocyte lineages. It is produced mainly by monocytes and macrophages and a variety of other cells like astrocytes, fibroblasts, and endothelial cells in response to specific stimulation, for instance by endotoxin, TNF-α, and IFN-γ. Furthermore, G-CSF enhances the survival and influences the immunological functions of mature neutrophils. Thus, in addition to its properties as a hematopoietic growth factor G-CSF also acts as a mediator of host defense against infections, and inflammatory response.
