Colonization of the UAW with S. aureus appears to contribute to the inflammatory process in CF to a higher extent than P. aeruginosa colonization (under antimicrobial medication), as patients colonized with S. aureus tended to show higher inflammatory mediators with significantly higher levels in IL-6, NE, and MMP-9 during the stable phase. The gene discussed is MMP9; the disease is cystic fibrosis.