IL26 and chronic obstructive pulmonary disease: To do this, we examined the respective correlation between, on the one hand, extracellular concentrations of IL-26 in BAL, BW, and IS samples from smokers with or without COPD and, on the other hand, forced expiratory volume (FEV)1% predicted and FEV1/forced vital capacity (FVC) (FEV%), collected during stable clinical conditions for each subject.