ACTA1 and chronic obstructive pulmonary disease: Patients with COPD had greater ADAM15 staining in AMs (Fig. 3a and Fig. E1), CD8+ T cells (Fig. 3b), and α-smooth muscle actin (α-SMA)-positive cells (likely myofibroblasts) around the small airways (Fig. 3c) than non-smokers and smokers.