Furthermore, TSLP protein expression statistically increased when cells were stimulated with ISs from COPD patients compared with untreated cells (p < 0.005) and decreased following the treatment with tiotropium (p < 0.003) or with ISs from COPD treated with anti-IL-17A Ab (p < 0.001) (Fig. 4b). This evidence concerns the gene IL17A and chronic obstructive pulmonary disease.