MMP9 and neoplasm: Neutrophils recruited by IL-8 enhance this effect by releasing proangiogenic factors such as vascular endothelial growth factor (VEGF) and Bv8, while tumor and TAM-secreted matrix metalloproteinase-9 (MMP-9) degrades the extracellular matrix (ECM), releasing sequestered VEGF to further promote vascularization [50,52,53].