Compared with Klotho+/+ (WT) mice, KLKO mice exhibited high plasma concentrations of FGF23 and 1,25(OH)2D3, hyperphosphatemia, and hypercalciuria, but not ionized Ca or PTH, as described previously (Figure 1a–f) (Ohnishi et al., 2009a). Here, KL is linked to hyperphosphatemia.