FGF23 and neoplasm: As abundant FGF23 protein can be produced by most TIO tumors [2, 11, 12] and the elevated serum FGF23 concentration decreases dramatically after complete tumor removal (the reported plasma half-life was 46–58 min [10]), the quantitative ELISA-like immunohistochemistry reported here is a feasible, reproducible procedure to detect the high FGF23 expression in paraffin-embedded biopsies or surgical specimens.