Notably, the magnitude of hypocalcemia in these studies was relatively small, as observed in prior studies [43,44]; however, Ca2+ concentration is maintained at the cost of hyper- or hypo-activations in multiple regulatory elements (serum Pi, vitamin D, PTH, FGF23/Klotho and CSR-mediated signaling) and active bone destruction. Here, FGF23 is linked to Hypocalcemia.