It has been claimed that myeloid-derived suppressor cells (MDSCs), which are precursors of DCs, macrophages, or granulocytes, have the ability to negatively regulate the immune response in cancer, with a subpopulation of monocytic MDSCs mediated by the EPOR-mediated Jak2/GATA3/STAT3 pathway induced (48). This evidence concerns the gene JAK2 and cancer.