IL4 and neoplasm: IL-4 can directly regulate the phenotypes and effector function of tumor-associated CD11b+Gr-1-F4/80+ macrophages, which were reported to promote the invasive and metastatic behavior of malignant mammary epithelial cells by secreting EGF and activating EGFR signaling programs in tumor epithelial cells (DeNardo et al., 2009).