The secreted factors include interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor-alpha (TNF-α), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF), which in turn promote not only tumor growth but also cancer metastasis in the tumor microenvironment (43). The gene discussed is CXCL8; the disease is neoplasm.