CXCL9 and chronic obstructive pulmonary disease: There were no differences in the responses of human primary airway epithelial cells derived from non-smokers, smokers or patients with COPD with respect to any of the stimuli examined (Fig 1B, 1D and 1F) These data suggest that BEAS-2B cells are a good model for the release of CXCL9, CXCL10 and CXCL11 from human airway epithelia and that human primary airway epithelial cells from COPD patients do not release greater levels of CXCL9, CXCL10 and CXCL11 than cells obtained from control subjects.