As the early detection of AKI is essential for improving treatment outcomes, biomarker candidates for AKI have been proposed, and these include cystatin C, kidney injury molecule-1, neutrophil gelatinase-associated lipocalin (NGAL), tissue inhibitor of metalloproteinase-2, and insulin-like growth factor (IGF)-binding protein-7 [13]. This evidence concerns the gene TIMP2 and acute kidney injury.