CSF2, also known as Colony Stimulating Factor 2 or Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF), is a protein that plays a crucial role in the immune system. It is produced by various cells, including T cells, macrophages, and fibroblasts, and is essential for the growth and differentiation of blood cells, particularly granulocytes and monocytes. In medical research, CSF2 is studied for its potential therapeutic applications, especially in treating conditions like cancer and autoimmune diseases. It helps stimulate the production of immune cells, enhancing the body's ability to fight infections and respond to diseases.