In particular, the protumor actions of neutrophils occur due to the production of proangiogenic factors (vascular endothelial growth factor, VEGF; prokineticin 2, PROK2; matrix metallopeptidase 9, MMP9), inhibition of the immune response (indoleamine 2,3-dioxygenase, IDO; arginase, ARG1), and stimulation of tumor cell proliferation (MMP9, elastase) [1, 4, 5]. This evidence concerns the gene MMP9 and neoplasm.