IFNB1 and chronic obstructive pulmonary disease: No significant difference was observed for IFNβ (median (range) (pg/mL): 0.44 (0–0.76); 0.46 (0–1.35) and 0.29 (0–1.38) (Kruskal Wallis, p = 0.767) respectively, for control non-smokers, control smokers, and mild/moderate COPD patients).