Elevated FGF23 concentrations are associated with cardiovascular events, infections, and death.24, , –27 Cinacalcet treatment was reported to reduce serum FGF23 concentrations, which was associated with the prevention of cardiovascular mortality and heart failure.28 In our study, the median changes in serum FGF23 after 24 weeks of upacicalcet and placebo treatment were 60% and 3%, respectively. The gene discussed is FGF23; the disease is heart failure.