CXCL8 and renal cell carcinoma: Overall, available data suggest that IL-8 has a relevant negative prognostic impact in a wide range of human malignancies; such impact may also have predictive value in the context of chemotherapy or immunotherapy treatments, while it is much less relevant in the context of treatment with anti-angiogenic agents, targeted therapy (with the notable exception of mTOR inhibition in advanced RCC), and combined therapies (anti-angiogenesis/immunotherapy/IT, chemotherapy/immunotherapy/IT).