Macrophage migration inhibitory factor(MIF) is a secreted protein and belongs to the MIF family. MIF is an important regulator of innate immunity. The circulating MIF binds to CD74 on other immune cells to trigger an acute immune response. Hence MIF is classified as an inflammatory cytokine. Furthermore glucocorticoids also stimulate white blood cells to release MIF and hence MIF partially counter acts the inhibitory effects that glucocorticoids have on the immune system. Finally trauma activates the anterior pituitary gland to release MIF.