Colony stimulating factors are glycoproteins that promote production of white blood cells (mainly granulocytes such as neutrophils), in response to infection. Administration of exogenous colony stimulating factors stimulates the stem cells in the bone marrow to produce more of the particular white blood cells. The new white blood cells migrate into the blood and fight the infection.
Colony stimulating factors are used in patients who are undergoing cancer treatment that causes low white blood cell counts (neutropenia) and puts the patient at risk of infection. Colony stimulating factors tend to reduce the time where patients are neutropenic.