In our study, the post-procedural delta NGAL significantly correlated with post-PCI SCr increase and CrCl reduction and, more interestingly, both the post-PCI NGAL increase and the 6-hours absolute values were significantly higher in patients who developed a SCr elevation greater than 0.24 mg/dl (i.e. 0.06 mg/dl below the threshold for identification of CI-AKI according to the AKIN criteria). This evidence concerns the gene LCN2 and acute kidney injury.