The aim of this study was to compare the serum levels of iFGF23, cFGF23, intact PTH (iPTH), 1,25(OH)2D3, 25(OH)D, Ca, P and sKl in patients with CKD undergoing haemodialysis with the control group and to reveal the pathophysiological role of these molecules in CKD. This evidence concerns the gene PTH and chronic kidney disease.