Another study by Isakova T. et al. showed the same results in a population of 3879 patients with CKD 2–4 and even in these patients with earlier stages of CKD, FGF-23 is a risk factor for mortality, where participants with a baseline estimated GFR > 30 mL/min/1.73 m2 were associated with greater risk of ESKD [66]. Here, FGF23 is linked to chronic kidney disease.