For example, culturing peripheral blood monocytes with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-4 and Prostaglandin-E2 (PGE2) or PGE2-expressing tumor cells generates cells with immunosuppressive functions and phenotypes similar to M-MDSCs [38,39]. The gene discussed is CSF2; the disease is neoplasm.