Various biomarkers for AKI incidence and progression to CKD using proteomics have been identified including exosomal fetuin-A (13, 14), zinc-α-2-glycoprotein (15), aprotinin (16), α-1 microglobulin (15, 17, 18), α-1 acid glycoprotein (15), albumin (15), β-2 microglobulin (17, 19), hepcidin-25 (20, 21), and uromodulin (12), although TIMP-2 and IGFBP7 are the only two FDA-approved biomarkers in the US and Europe (22). The gene discussed is TIMP2; the disease is acute kidney injury.