The close interplay among these mediators is demonstrated by the up-regulation of CXCL5 and CXCL8 expression in human non-small cell lung cancer cells and of CXCL1 in colorectal cancer cells induced by PTGS2 (Pold et al., 2004; Wang et al., 2006). The gene discussed is PTGS2; the disease is colorectal cancer.