IL6 and chronic obstructive pulmonary disease: In a univariate analysis, each predictive marker proved to be significantly correlated with median PFS, such as the GOLD score for COPD (HR = 1.7, p = 0.034) and the plasma levels of IL-6 (HR = 1.001, p = 0.003), IL-8 (HR = 1.014, p = 0.005), and IL-10 (HR = 1.049, p = 0.014).