Since airway epithelial ICAM-1 expression is upregulated in P. aeruginosa infection, is a feature of CF lung disease and mediates neutrophilic inflammation in the lung, this led us to investigate the effect of lasR mutants on membrane bound ICAM-1 (mICAM-1) in AEC and its contribution to neutrophilic inflammation in vitro and in vivo. The gene discussed is ICAM1; the disease is cystic fibrosis.