CXCL8 and chronic obstructive pulmonary disease: Treatment of cells with Sul-121 dose-dependently reduced 15% CSE-induced IL-8 release up to 90%, with 300 μM Sul-121 almost fully abrogating IL-8 release (p < 0.001); an effect on par with that elicited by 1 μM fenoterol, a first line COPD therapeutic28 (Fig. 5A).