The BAL level of soluble ST2 (p=0.0073; figure 3D) and IL-1RA (p=0.0307; figure 3B) are significantly decreased in patients with stable COPD compared with control smokers with normal lung function without significant changes in the BAL level of IL-1β (see online supplementary figure E6B), IL-18 (see online supplementary figure E6C), IL-18BPa (see online supplementary figure E6D) and their IL-1β/ILRA (see online supplementary figure E6E) and IL-18/IL-18BPa (see online supplementary figure E6F) ratios and IL-37 between the two group of subjects. The gene discussed is IL18; the disease is chronic obstructive pulmonary disease.