IL10 and asthma: SR asthma patients have a defect in the dexamethasone-driven IL-10 response (6, 9, 10) and heightened levels of IL-17A; indeed, levels of IL-17A inversely correlate with lung function (11) and are significantly elevated in the peripheral blood (6, 7, 12), sputum (13), serum (14, 15), and bronchial alveolar lining fluid (16, 17) of patients with severe asthma, with the greatest levels observed in patients with SR disease (7).