The characteristic lung tissue destruction witnessed in COPD subjects [27] could, therefore, be partially mediated by the cytotoxic cells identified in this study, as they all express characteristic sets of chemokine receptors and adhesion molecules that are required for homing to inflamed tissues, such as CXCR3, whose ligand IP-10 is known to be up-regulated in COPD lung epithium [44]. This evidence concerns the gene CXCR3 and chronic obstructive pulmonary disease.