Introduction of Colony-stimulating factors (CSFs)

Colony-stimulating factors (CSFs) are secreted glycoproteins.  macrophage colonystimulating factor (M-CSF; also known as CSF1),Granulocyte/macrophage colony-stimulating factor (GM-CSF; also known as CSF2) and granulocyte colony-stimulating factor (G-CSF; also known as CSF3) were first defined by their abilities to generate in vitro colonies of mature myeloid cells from bone-marrow precursor cells following the proliferation and differentiation of these cells — granulocytic and macrophage colonies in the case of GM‑CSF, macrophage colonies for M‑CSF and granulocytic colonies for G‑CSF. It later became clear that these CSFs could also act in vitro on mature myeloid cells and therefore might have broader roles in an immune response than acting simply as haematopoietic-cell growth factors.