Specifically, the chemokine IL8 has been shown to underpin the angiogenic response of HIF-1α–deficient/VEGF-depleted DLD-1 colon cancer xenografts (31), and mediate the resistance of head and neck squamous cell carcinoma and renal cell carcinoma to Bevacizumab (32) and Sunitinib (33), respectively. This evidence concerns the gene HIF1A and renal cell carcinoma.