Description: Granulocyte Colony Stimulating Factor (G-CSF) is a member of the IL-6 cytokine family. It is 207 amino acids long with one glycosylation site and two disulfide bonds. G-CSF can be expressed by many different cell types including fibroblasts, endothelial cells, monocytes, macrophages and bone marrow stromal cells. Production of G-CSF is upregulated in response to infection and inflammatory mediators such as IL-1 beta, TNF alpha, and LPS. IL-17 has also been shown to regulate the production of G-CSF. The receptor for G-CSF is structurally similar to type I cytokine receptors. The receptor is expressed on both hematopoietic and non-hematopoietic cells. Within the hematopoietic cells, G-CSF receptor is expressed predominantly on cells of myeloid origin, including granulocytes and monocytes but not on erythrocytes, lymphocytes or eosinophils. G-CSF receptor activates the Jak/STAT signaling pathway. G-CSF activates and mobilizes granulocytic precursors from the bone marrow and supports the proliferation, activation and differentiation of neutrophils in the blood.