IL1B and chronic obstructive pulmonary disease: While AIM2 immunofluorescence in epithelial cells from healthy controls was dull (Fig. 5a, middle and right panels) or moderate (5A, left panel), there was a bright cytoplasmic staining for AIM2 in epithelial cells from COPD patients, often associated with specks of cleaved IL-1β (Fig. 5b), which was hardly detected in control.