CXCL8 and infection: Among the three groups of patients, there were significant differences in IL-6, IL-8, IL-10, IFN-γ, IL-17A, and IL-17F between the non-infection group and the pulmonary bacterial infection group (P < 0.05) as given in Table 2, Fig. 1D–F, and Supplementary Fig. 1D–F.