BMP4 and chronic kidney disease: The precise function of MGP hasnot been elucidated, but may include calcium crystal growth, blockage of bone morphogeneticprotein (BMP)-2 and BMP-4 functions, and inhibition of vascular calcification [16,26].Low levels of vascular calcification are present in predialysis CKD, and vascularcalcification significantly increases in patients on dialysis [25].