Vascular calcification can be observed in chronic renal diseases, and metaplasia of VSMC to an osteoblastic phenotype linked to increasing expression of BMP-2 and BMP-3 is a feature of this vascular calcification in diabetes.[25,26] The growth stimulating activity of OIF on bone acts through increased expression of BMP-2 and BMP-3, indicating that OIF would be expected to increase in DN. This evidence concerns the gene OGN and calcification.