Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a protein that plays a crucial role in the immune system. It stimulates the production and function of granulocytes and macrophages, which are types of white blood cells essential for fighting infections and responding to inflammation. GM-CSF is produced by various cells, including T cells, macrophages, and fibroblasts. In medical research, GM-CSF is studied for its potential in treating certain diseases, such as cancer and autoimmune disorders. It can enhance the immune response, making it a candidate for therapies aimed at boosting the body's ability to combat diseases.