IL6 and chronic obstructive pulmonary disease: In addition, the correlation of serum hs-CRP, IL-6, IL-10, ET-1, and COPD-PH severity was analyzed, and it turned out that hs-CRP, IL-6, and ET-1 were positively correlated with COPD-PH severity, and IL-10 was negatively correlated with COPD-PH severity, which indicated that serum hs-CRP, IL-6, IL-10, and ET-1 were closely related to the severity of the disease and may be used as predictors for the disease.