IGFBP7 and acute kidney injury: Kidney injury biomarkers, such as functional biomarkers (CysC), damage biomarkers (KIM-1, L-FABP, IL-18, suPAR, and NGAL), and stress biomarkers (TIMP-2 and IGFBP7), appear to be efficient in detecting AKI as well as disease progression in patients with COVID-19.