MIF and neoplasm: Of the potential small molecule inhibitors of MIF signaling, ibudilast has gained a great attention due to its strong anti-inflammatory effect and suppressive effect of MDSCs by MCP-1 inhibition via blocking MIF signaling.45 Of note, it can lead to the most powerful reduction of MDSC generation compared with other MIF inhibitors 4-IPP and ISO-1.45 Ibudilast can also contribute to cancer treatment via increasing CD8+ T cell infiltration and suppressing MDSC functions in tumor microenvironments45 46 in a MIF-dependent manner.