Based on our present result, it could be estimated that around 3200 patients will be required to ensure an adequate sample size to discern a meaningful difference in hemoglobin level for various stages of CKD.[28] Theoretically, the analysis of serum C-reactive protein levels and the change in reticulocyte count before and after DPP-4 inhibitor treatment will further support our hypothesis. This evidence concerns the gene DPP4 and chronic kidney disease.