IL6 and infection: Median maximum concentrations of both IL-6 and CRP within 24 hours from the start of surgery were higher in patients with postoperative infection (135.0 pg/ml (IQR 80.0,180.5) vs. 80.5 pg/ml (54.8,131.5), p = 0.003 and 58.4 mg/L (38.2,88.6) vs. 44.4 mg/L (29.5,60.2), p = 0.009 for IL-6 and CRP respectively (S1 File).