HMGB1 and chronic obstructive pulmonary disease: BAL levels of HMGB1 have been reported as either increased in patients with stable COPD41 or no different from controls.43 In steroid-naïve patients with stable COPD, we found significantly decreased BAL HMGB1 levels, in comparison with age-matched control smokers with normal lung function, although this difference was lost when outliers were removed, again suggesting a minor role of inflammasome activation in the peripheral airways or a role limited to a subset of COPD patients only.