M1 macrophages are activated by lipopolysaccharides (LPS) and interferon-gamma (IFN-γ) to produce proinflammatory cytokines, such as IL6, CXCL10 etc. However, TAMs are thought to resemble M2 macrophages, which are activated by IL-4, IL-10, IL-13 and produce IL-10, CCL22 etc. Recently, it has been reported that M2 macrophages promote tumor development through exosome-mediated communication with tumor cells 11, 12. The gene discussed is CCL22; the disease is neoplasm.