DKK3 and chronic kidney disease: Previous research suggests that uDKK3, a profibrotic glycoprotein, is associated with AKI, short-term GFR decline, and progression of CKD.8, 9, 10 DKK3 is produced by stressed renal tubular cells, and uDKK3 is almost exclusively of renal tubular cell origin, making it especially suitable for detecting early tubular injury.11, 12, 13 The studies so far have mostly focused on uDKK3 as biomarker of GFR decline in subjects with existing CKD, employing eGFR from serum levels of Cr.