MIF and neoplasm: Pharmacological targeting of MIF by a small molecule antagonist, 4-iodo-6-phenylpyrimidine (4-IPP) also reduced tumor growth by reduction of ArgI and elevation of TNF-α expression in TAM, furthermore 4-IPP attenuated TAM and both splenic Gr1high Ly6G+ G-MDSC and Gr1dim, Ly6G− M-MDSCs mediated immunosuppression [158].