As shown in Figure 2, we found that the levels of inflammatory factors in the peripheral blood of patients with bronchiectasis were higher in P. aeruginosa (+) group than in P. aeruginosa (–) group, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), soluble interleukin 2 receptor (SIL-2R) and tumor necrosis factor-α (TNF-α). Here, TNF is linked to bronchiectasis.