Second, to strengthen our results on the role of PSP/reg as a marker of renal injury and inflammation in the disease progression of DKD, correlations with serum cystatin C (Cys C), homocysteine (Hcy) and other inflammatory markers such as C reactive protein (CRP), tumor necrosis factor-alpha (TNF-α) are needed. The gene discussed is TNF; the disease is diabetic kidney disease.