Colony-Stimulating Factors, CSFs

Colony-stimulating factors (CSFs) are secreted glycoproteins that bind to receptor proteins on the surfaces of committed progenitors in the bone marrow, thereby activating intracellular signaling pathways that can cause the cells to proliferate and differentiate into a specific kind of blood cell (usually white blood cells). The name "colony-stimulating factors" comes from the method by which they were discovered. The substance that was found to stimulate formation of colonies of macrophages, for instance, was called macrophage CSFs, for granulocytes, granulocyte CSFs, and so on. Colony-stimulating factors include: macrophage CSFs (CSF1), Granulocyte macrophage CSFs (CSF2, also called GM-CSF and sargramostim), Granulocyte CSFs (CSF3, also called G-CSF and filgrastim), Interleukin 3 etc.