Evaluation of changes in the mean values of IL-18 in all examined patients showed an excess of the level of this cytokine in patients with COPD, asthma-COPD overlap, and BA compared with healthy individuals by 4-4.8 times (100.5 [68.2; 123, 3 pg/ml, ANOVA p ≤ 0.0001) (Figure 4). Here, IL18 is linked to asthma.