CXCL8 and neoplasm: In addition, we found that the administration of the CXCL8 neutralising antibody to FPS xenografts had reduced the amount of cytokeratin 18 positive immunoreactivity (as indicated by the brown staining) thereby confirming a reduction in the epithelial cell component of the xenograft tumours (Fig. 7B and C, P < 0.001).