IL4 and neoplasm: Th2 cells produce IL-4 and IL-10 to induce M2 polarization of macrophages; M2 macrophages secrete CCLs to recruit Th2 cells, while secreting IL-1β, IL-6, and IL-10 to induce M2 polarization of macrophages continuously; TNF-α and IL-1β secreted by M2 macrophages directly recruit neutrophils, and inflammation enhances the endothelial adhesion and migration of neutrophils; IL-8 and IL-6 induce the M2 polarization of neutrophils to play a synergistic role in promoting tumor development.