COL4A3 and Hypertension: Models of FGF23 excess such as αKlotho-knockout mice, Col4a3-knockout mice, Fgf23-Tg mice, 5/6-nephrectomized rats and spontaneously hypertensive rats (SHRs) develop cardiac hypertrophy, but these models develop simultaneously hypertension, hyperphosphatemia or secondary hyperparathyroidism, which by themselves may lead to LVH [204,205,213,216].