IFN-gamma, or Interferon-gamma, is a type of protein known as a cytokine, which plays a crucial role in the immune system. It is primarily produced by T cells and natural killer cells in response to infections and other immune challenges. IFN-gamma helps activate immune cells, enhancing their ability to fight off pathogens and regulate the immune response. In addition to its role in fighting infections, IFN-gamma is important for maintaining the balance of the immune system. It promotes the development of macrophages, which are essential for clearing away dead cells and pathogens. Abnormal levels of IFN-gamma can be associated with various diseases, including autoimmune disorders and chronic infections.