Along with the importance of glomerular damage in DKD, renal tubulointerstitial injuries may also play an important role in the development and progression of DKD.[4,5] Recently, several tubular damage markers, including kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, N-acetyl-β-d-glucosaminidase (NAG), heart fatty acid–binding protein, and cystatin C, have gained considerable attention because of their clinical implications as sensitive and specific biomarkers for predicting the development and progression of early stage DKD.[6–10]. Here, CST3 is linked to diabetic kidney disease.