Macrophages can be divided into M1 type and M2 type macrophages: M1-type macrophages have anti-tumor characteristics and secrete pro-inflammatory factors such as IL-6, IL-8, IL-1β, IFN-γ, and TNF-α, whereas M2-type macrophages have tumor-promoting properties and secrete anti-inflammatory factors such as IL-10, IL-4, epithelial growth factor (EGF), TGF-β, and IL-19, thereby playing an important role in promoting tumor cell proliferation and migration [40, 41]. Here, CXCL8 is linked to neoplasm.