Other independent variables were APACHE II score day 1, SOFA score day 1, CRP day 1, IL-6 day 1, bilirubin day 1, AST day 1, creatinine day 1, need of renal replacement therapy day 1, age, sex, body mass index (BMI), need of invasive ventilation day 1, norepinephrine > 1.0 mg/h day 1, infection focus, and estimated mortality based on APACHE II score day 1. This evidence concerns the gene IL6 and infection.