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. CSF-1 induces cells of the monocyte/macrophage lineage. It plays a role in immunological defenses, bone metabolism, lipoproteins clearance, fertility and pregnancy.
Glycosylation and proteolytic cleavage yield different soluble forms. A high molecular weight soluble form is a proteoglycan containing chondroitin sulfate. Isoform 1 is N- and O-glycosylated. Isoform 3 is N-glycosylated.