CXCL8 and neoplasm: Hypoxia in the tumor microenvironment causes tumor cells to secrete chemokines, such as interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-alpha), or interleukin 8 (IL-8), which activates neutrophils to produce more pro-oncogenetic and immunosuppressive factors (Ardi et al., 2007).