For instance, changes in cardiac size have not been seen in hyp mice up to the age of 30 weeks (24), and neutralizing FGF23 a) did not prevent cardiac hypertrophy in rats that underwent subtotal nephrectomy, and b) increased mortality, this may reflect different effects of FGF23 blockade based on the underlying mechanisms of excess (25). This evidence concerns the gene FGF23 and cardiac hypertrophy.