– Macrophage Colony-Stimulating Factors (m-csf) are cytokines that act in hematopoiesis by controlling the production, differentiation, and function of 2 related white cell populations of the blood, the granulocytes and themonocytes-macrophages. CSF-1 promotes the release of proinflammatory chemokines, and thereby plays an important role in innate immunity and in inflammatory processes. It also plays an important role in the regulation of osteoclast proliferation and differentiation, the regulation of bone resorption, and is required for normal bone development. CSF-1 is required for normal male and female fertility and promotes reorganization of the actin cytoskeleton, regulates formation of membrane ruffles, cell adhesion and cell migration. it also plays a role in lipoprotein clearance.