Table 1 summarizes relevant studies reporting FGF23 levels and its function in several cancer types. An anti-FGF23 approach may be useful in malignancies affecting bone because they are characterized by enhanced FGF23 levels or FGF23 signaling. In other tumor entities (e.g. endometrial cancer, hepatocellular carcinoma), no change in serum FGF23 level was demonstrated (70). Here, FGF23 is linked to cancer.