MMP9 and neoplasm: The tumor-promoting effects of neutrophils were ascribed to production of nitric oxide radicals contributing to DNA damage54, to expression of metalloproteinase (MMP)-9 and neutrophil elastase (NE) driving angiogenesis and enhanced tumor cell proliferation38, to myeloid-derived suppressor cell (MDSC) activity and inhibition of CD8+ T cell functions36, and also to increased pro-inflammatory chemokine and cytokine secretion.