M2 TAMs also promote angiogenesis of tumor cells by secreting vascular endothelial growth factor (VEGF) and IL-17, and can release matrix metalloproteinase (MMP)-2, MMP-9 and other substances to degrade extracellular matrix, promote vascular endothelial migration and induce angiogenesis (100, 101). This evidence concerns the gene VEGFA and neoplasm.