Figure 1: Comparison of the preoperative serum interleukin-6 levels among patients with postoperative acute kidney injury staged according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The box plots show the median (line in the middle of the box), interquartile range (box), 5th and 95th percentiles (whiskers), and outliers (dots). versus no AKI development.