Furthermore, NGAL levels were significantly associated with the severity of renal impairment (no AKI: 75.4 ng/ml (60.0 to 113.9) versus AKI stage 1: 101.8 ng/ml [(1.0 to 193.8) versus AKI stage 2: 120.9 ng/ml (60.0 to 210.7) versus AKI stage 3: 231.5 ng/ml (174.8 to 479.3); P < 0.001). This evidence concerns the gene LCN2 and acute kidney injury.