CXCL8 and neoplasm: Neutrophils not only inhibited the lymphocyte-mediated immune system (mainly T-cell activation) to promote tumor proliferation by secreting numerous inflammatory mediators, such as interleukin (IL)-6, IL-8, and vascular epithelial growth factor (17, 18) but also enhanced adhesion and distant metastasis of circulating tumor cells (CTCs) (19, 20).