FGF23 and McCune-Albright syndrome: Some types of rickets and osteomalacia such as X-linked hypophosphatemic rickets/osteomalacia, hypophosphatemic rickets/osteomalacia associated with McCune-Albright syndrome/fibrous dysplasia, and tumor-induced rickets/osteomalacia show hypophosphatemia and an increased FGF23 level[23-27].