M-CSF,CSF1,CSF-1,Macrophage colony-stimulating factor 1,also known as CSF-1,M-CSF,Lanimostim and CSF1,is a single-pass membrane protein which is disulfide-linked as a homodimer or heterodimer. Granulocyte / macrophage colony-stimulating factors 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 the monocytes-macrophages. M-CSF/CSF-1 is known to facilitate monocyte survival,monocyte-to-macrophage conversion,and macrophage proliferation. M-CSF/CSF-1 is a secreted cytokine which influences hemopoietic stem cells to differentiate into macrophages or other related cell types. It binds to the Colony stimulating factor 1 receptor. M-CSF/CSF-1 may also be involved in development of the placenta. The active form of M-CSF/CSF-1 is found extracellularly as a disulfide-linked homodimer,and is thought to be produced by proteolytic cleavage of membrane-bound precursors. M-CSF/CSF-1 induces cells of the monocyte/macrophage lineage. It also plays a role in immunological defenses,bone metabolism,lipoproteins clearance,fertility and pregnancy. Upregulation of M-CSF/CSF-1 in the infarcted myocardium may have an active role in healing not only through its effects on cells of monocyte/macrophage lineage,but also by regulating endothelial cell chemokine expression.