Previous studies also confirmed that circulating FABP4 depended on renal function in CKD and AKI patients.21,22 Urinary FABP4 level also could predict yearly decline of renal function and would be a new marker of kidney damage.23 Other than macrophages and adipocytes, it has been reported that FABP4 is expressed in the glomerulus and tubular cells in patients with CKD.24 Moreover, FABP4 expression in the kidneys induced by CKD is closely associated with renal dysfunction.24 This evidence concerns the gene FABP4 and acute kidney injury.