TANs acquire an N2 pro-tumor phenotype due to their high expressions of metastasis chemoattractants in the tumor microenvironment such as MMP9, IL-6, NE and low expression of ICAM-1, etc. Neutrophils are considered as the potent initiators of angiogenesis because they could release MMP-9 that contributes to tumorigenesis. The gene discussed is MMP9; the disease is neoplasm.