Fig. 5. Cytokine levels in plasma. Levels of interleukin (IL)-6, keratinocyte-derived chemokine (KC), IL-10, and tumor necrosis factor-α in unventilated (C) and ventilated (V) wild type (WT) and Toll/interleukin-1 receptor domain-containing adapter-inducing interferon-β (TRIF) mutant mice ( panels A–D ). Mechanical ventilation in WT mice (group V-WT) increased IL-6 ( P < 0.001) and KC ( P < 0.001) in plasma when compared with unventilated WT mice (group C-WT). In TRIF mutant mice (group V-TRIF), no increase in IL-6 was found after mechanical ventilation when compared with the unventilated TRIF mutant mice (group C-TRIF). Mechanical ventilation in TRIF mutant mice (group V-TRIF) did increase levels of KC ( P < 0.001) when compared with unventilated TRIF mutant mice (group C-TRIF). This was not statistically different from ventilated TRIF mutant mice (group V-TRIF). n = 8 for all groups. Data are expressed as box (median, 25th, 75th percentile) and whiskers (range). *= P < 0.05 compared with unventilated mice. When no BbTox and whiskers are visible, all levels remained below detection limit.