This includes various conditions such as tumor-induced osteomalacia caused by the overproduction of FGF23 due to phosphaturic mesenchymal tumors, hypophosphatemia associated with the intravenous administration of iron preparations, and genetic disorders, such as ADHR, XLH, ARHR1, ARHR2, and RNS (4). Here, FGF23 is linked to mesenchymal cell neoplasm.