Macrophage colony-stimulating factor (M-CSF) is a protein that plays a crucial role in the immune system. It is primarily responsible for the growth and differentiation of macrophages, which are essential white blood cells that help the body fight infections and clear away dead cells. M-CSF signals precursor cells in the bone marrow to develop into macrophages, enhancing the body’s ability to respond to pathogens. In addition to its role in immune response, M-CSF is involved in various physiological processes, including tissue repair and inflammation. It can also influence the behavior of other immune cells, making it an important factor in maintaining overall health and homeostasis in the body.