CXCL8 and metastatic neoplasm: It should be noticed that although the density of hypoxic foci, IL-8 positive foci and vascular hot spots differed significantly between metastatic and non-metastatic primary tumours, a substantial fraction of the non-metastatic tumours showed density values for hypoxic foci, IL-8 positive foci and vascular hot spots within the same ranges as those for the metastatic tumours (Figure 4).