FGF23 and hypophosphatemia: In extension to previously published studies, our results support the hypothesis that both altered parameters of mineral metabolism and elevated FGF23 levels contribute to cardiac hypertrophy and fibrosis in the setting of klotho deficiency, and consequently, Hyp mice might be protected from pathologic cardiac remodeling by the presence of concomitant hypophosphatemia and lack of hypercalcemia.