IL4 and neoplasm: In contrast, M2-type macrophages promote tumor progression by secreting anti-inflammatory cytokines, IL-1, IL-4, IL-10, and pro-angiogenic factors, vascular-endothelial-growth-factor (VEGF), IL-8, recruiting Tregs and MDSCs, and releasing matrix metalloproteinases (MMPs) to remodel the ECM, aiding metastasis (9, 41, 42, 44, 45).