In our study, the degree of OPG staining, together with the degree of CD34 and a-SMA expression, were the only independent parameters correlating to the degree of vascular calcification, indicating that endothelial cell activation, myofibroblast formation and OPG pathway are mainly implicated in the development of vascular calcification in CKD patients. This evidence concerns the gene TNFRSF11B and chronic kidney disease.