However, neutrophils can cause DNA damage through reactive oxygen species and related products of myeloperoxidase (MPO), and N2 cells secrete VEGF, TNF and other cytokines to promote tumor angiogenesis and, at the same time, synthesize and secrete MMP and NE to the tumor stroma to participate in the tumor reconstruction of the extracellular matrix to promote tumor growth and metastasis (Zvi et al., 2009; Mishalian et al., 2013; Zhou et al., 2016). The gene discussed is MPO; the disease is neoplasm.