CXCL8 and neoplasm: Macrophages infiltrating the tumor microenvironment however are usually activated along the M2 pathway promoting Th2 type immune responses [29] and tumor progression by releasing proangiogenic cytokines and growth factors (VEGF, IL-8, b-FGF) and matrix metalloproteases (MMPs) that digest the tumor basement membrane, facilitating tumor metastasis [30].