TIMP2 and acute kidney injury: It is not known what proportion of physicians use novel AKI biomarkers in their clinical practice, but estimates are quite low—even among those with a critical care nephrology focus.20 TIMP-2 and IGFBP7 were incorporated into a clinical laboratory test, the NephroCheck test, which received US Food and Drug Administration approval in 2014.21 NGAL use was first reported clinically in 2017.22 We use these tests daily in our clinical practice and find utility in them.