**5.3 Interleukin-8 (IL-8)**

Interleukin-8 (IL-8) is a multifunctional CXC chemokine that is involved in the immune response of neutrophils in humans including kinetic phenomena, enzyme release and expression of surface adhesion of molecule. IL-8 also has a direct effect on tumor progression, including the proliferation of vascular endothelial cells and formation of new vessels. In addition, IL-8 increases the likelihood of metastases and new tumor formation in the liver [82]. A study showed that IL-8 serum concentrations increased in HCC patients compared to healthy subjects, it was positively correlated with tumor size (≥5 cm), portal vein thrombosis and advanced stage with lymph node metastases [83]. Therefore, it may be a biological marker that plays a useful role in HCC diagnosis and prognosis.
