Among 133 patients without a preexisting AKI diagnosis at the time of ICU admission, CART analysis showed no significant difference between their performances; the AUC-ROC of NGAL and L-FABP was 0.759 (95% CI 0.667–0.850) and 0.746 (95% CI 0.662–0830), respectively. The gene discussed is LCN2; the disease is acute kidney injury.