CXCR2 and neoplasm: Notably, ligands (Cxcl1, Cxcl2, Cxcl3, Cxcl5) for the chemokine receptor CXCR2, the latter identified as being predominantly expressed by Ly6G+ neutrophils, were all increased in tumour tissue (figure 2D, E and online supplemental figure 2F).