A recent study reported that plasma and urine NGAL had relatively low predictive values for use of RRT in ICU patients with severe sepsis and, even excluding patients with chronic kidney disease, the AUCs were 0.73 (95 % CI: 0.61–0.85; P = 0.64) and 0.68 (95 % CI: 0.53–0.83; P = 0.52), respectively [29]. Here, LCN2 is linked to chronic kidney disease.