FGF23 and Hypercalcemia: Although both Scl34a1−/− mice and Fgf23−/−Scl34a1−/− mice showed hypophosphatemia and hypercalcemia, the marked increase of osteoid was observed in Fgf23−/−Scl34a1−/− mice but not in Scl34a1−/− mice [19].