FGF23 and chronic kidney disease: Cardiac FGF23 levels are associated with the up-regulation of FGFR4 and activation of the calcineurin-NFAT signaling pathway, an established mediator of cardiac remodeling and LVH, indicating a strong relationship between LVH and elevated expression levels of FGF23, FGFR4, and calcineurin, as well as the activation of nuclear factor of activated T cells (NFAT) in the myocardium of patients with CKD (Leifheit-Nestler et al., 2016).