Statistical analyses indicated that concentration levels of the remaining eight cytokines under study showed significant differences between study groups, with higher levels of IL-1Rα1, IL2, IL4, IL8, IL9, IL13, IL17, and CCL11 for COPD-BS than COPD-TS (Table 2; Figure 1). This evidence concerns the gene CXCL8 and chronic obstructive pulmonary disease.