However, after adjustment for modified SOFA and CKD, C3 value higher than median was significantly associated with a lower risk for AKI stage 2 or 3, compared to no AKI or AKI stage 1 (OR 0.17 95% CI [0.05–0.54], p = 0.004), while the association between AKI stage 2 or 3 and IL-6, Ferritin, sC5b9 and PEEP levels did not reach statistical significance (Additional file 1: Table S1 and Figure S1). This evidence concerns the gene IL6 and chronic kidney disease.