FGF23 and neoplasm: Complete and definitive surgical resection is the first choice treatment for TIO.[4,16] Octreotide replacement therapy has also been shown to be useful for octreotide-positive patients.[17,18] Phase I clinical trials indicated that anti-FGF-23 antibodies were effective and safe in adult patients with XLHR, and this therapy may be applicable for TIO patients in the future.[19] Patients should also be routinely administered phosphate and vitamin D if the tumor location could not be defined.