MIF and central nervous system cancer: However, in other tumors MIF secretion is associated with increased intratumoral mMDSCs [54] and adding an inhibitor of MIF’s keto-enol tautomerase activity to tumor supernatant has decreased the formation of mMDSCs.[55] One group has gone as far as to call MIF, “MDSC inducing factor”, due to its ability to increase mMDSCs in the tumor microenvironment.[56] Otvos et al have recently described MIF’s role in generating MDSCs in both murine glioma models and patient-derived specimens [57].