MIF and cancer: Furthermore, the MIF, a pro-inflammatory cytokine, plays an important role in regulation of the innate and adaptive immune responses, alteration of which was associated with development of different human cancers; for example, the MIF signaling pathway was able to upregulate expression of various cancer-promoting genes, which can not only act directly on tumors, but also promote tumorigenesis by acting on tumor microenvironment [36, 37].