In addition, they found increasing serum intact Fgf23 levels in mice and rats after experimental MI, and immunohistochemical staining of heart tissue clearly reveals expression of Fgf23 in left ventricular cardiac myocytes after MI in mice and rats but not in infiltrating leukocytes within the infarct scar, suggesting that cardiac myocytes are the major cellular source of increased cardiac Fgf23 expression post-MI. Here, FGF23 is linked to myocardial infarction.