FGF23 and chronic kidney disease: The question whether FGF23 has direct effects on blood vessels is a controversial issue.Some studies reported a positive association between circulating FGF23 and arterialstiffness (Mirza, Larsson, et al.2009), total body atherosclerosis (Mirza, Hansen, et al. 2009), coronary arterycalcification (Morita et al.2015; Hu et al. 2015), andcarotid atherosclerosis (Shah et al.2015) in normal subjects, whereas other studies failed to provide evidence for alink between atherosclerosis or atherosclerotic events and serum FGF23 in CKD patients(Seiler et al. 2014; Sarmento-Dias et al. 2016).