We found a diagnostic OR of 5.11 (95 % CI 3.22–8.12) for urine IL-18 level to predict AKI (Cochran-Q = 28.19, p = 0.0017) with a sensitivity and specificity respectively of 0.51 (heterogeneity Chi-squared 84.53, p < 0.001) and 0.79 (heterogeneity Chi-squared 62.84, p < 0.001) (Fig. 3). The gene discussed is IL18; the disease is acute kidney injury.