Numerous studies have demonstrated that PENK can detect AKI with sensitivity comparable to or superior to that of other established biomarkers, such as Neutrophil gelatinase-associated lipocalin (NGAL) and Tissue inhibitor of metalloproteinases 2 (TIMP-2) × Insulin-like growth factor-binding protein 7 (IGFBP-7). The gene discussed is TIMP2; the disease is acute kidney injury.