Macrophage migration inhibitory factor(MIF) is also known as Glycosylation-inhibiting factor(GIF), L-dopachrome isomerase, L-dopachrome tautomerase, Phenylpyruvate tautomerase. Interacts with CXCR2 extracellular domain, CD74 extracellular domain, COPS5 and BNIPL. The expression of MIF at sites of inflammation suggests a role as mediator in regulating the function of macrophages in host defense. Counteracts the anti-inflammatory activity of glucocorticoids. Has phenylpyruvate tautomerase and dopachrome tautomerase activity (in vitro), but the physiological substrate is not known. It is not clear whether the tautomerase activity has any physiological relevance, and whether it is important for cytokine activity.