FGF23 and hyperphosphatemia: Additionally, Bansal et al. described a patient with tumor-induced osteomalacia and elevations in serum concentrations of both FGF7 and FGF23.[11] Interestingly, a recent study showed that low serum FGF7 concentrations were observed in pediatric patients with hypophosphatasia and hyperphosphatemia.[12] Moreover, the intravenous FGF7 administration increased the fractional excretion of phosphate in vivo in rats, suggesting that hyperphosphatemia in pediatric hypophosphatasia might be partly attributable to FGF7 insufficiency.