Figure 3b illustrates the diagnostic value to rule out clinically apparent infections on admission to ICU: IL-6ascites had a sensitivity of 81.8% and a specificity of 86.8% (AUC = 0.904), with a cut-off < 1719 pg/mL. We found a PPV of 63.6% and an NPV of 92.5%. IL-6ascites performed better in identifying “no infection” than IL-6serum (AUC = 0.855), CRP (AUC = 0.778), or PCT (AUC = 0.767). This evidence concerns the gene CRP and infection.