FGF23 and chronic kidney disease: On the other hand, vascular calcification is a frequent findingin patients with CKD, and it is conceivable that high circulating levels of intact FGF23such as those found in CKD patients might exert Klotho-independent effects on blood vessels.However, the majority of studies in vascular smooth muscle cells or organ cultures ofarteries did not suggest a direct calcification-promoting effect of FGF23 or a directmodulating effect of FGF23 on arterial dilatory or contractile functions (Lindberg et al. 2013; Scialla et al. 2013).