Neutrophils can also support tumor angiogenesis by producing vascular endothelial growth factor (VEGF), prokineticin 2 (PROK2), and MMP9 [14,15], whereas cathepsin G, a neutrophil-derived serine protease, enables the formation of tumor cell aggregates that can further spread to distant sites leading to the development of metastases [10,16]. The gene discussed is MMP9; the disease is neoplasm.