KL and chronic kidney disease: Leifheit-Nestler andcoworkers (2016) demonstrated that FGF23 expression is increased in cardiomyocytesof CKD patients with left ventricular hypertrophy (Figure 1). Similarly, FGF23 expression was shown to beincreased in peri-infarct cardiomyocytes in rodent models of acute myocardial infarction(Andrukhova et al. 2015). Inaddition, there is evidence that at high circulating concentrations, FGF23 is apro-hypertrophic molecule, acting directly on cardiomyocytes via a Klotho-independent,FGFR4-mediated signaling pathway (Faulet al. 2011; Grabner et al.2015).