Analyzing the percentage of IL-18 increase from the initial value in the consecutive time points, it was noted that in patients with AKI, there was a significantly higher increase in IL-18 urine concentration 6 h after weaning from CPB (M = 122.02 (100–204.21)% vs. 89.80 (77.97–112.53)% in the control group, p = 0.002). This evidence concerns the gene IL18 and acute kidney injury.