In our previous case-control study, we evaluated FGF23 function in hypoparathyroid patients compared to a healthy population, and we find that although the FGF23 is a main regulator of urinary phosphate excretion but the existence of sufficient parathyroid hormone is necessary for the full phosphaturic effect of FGF23 [28]. The gene discussed is PTH; the disease is hypoparathyroidism.