Until now, there have been four major categories of biomarkers for AKI in these patients: functional markers, such as serum creatinine; up-regulated proteins, such as NGAL and IL-18; low molecular weight proteins, such as urine cystatin C; and enzymes, such as alpha-glutathione s-transferase and pi-glutathione s-transferase [10]. Here, LCN2 is linked to acute kidney injury.