FGF-23 is a member of the fibroblast growth factor （FGF） family. FGF family members possess broad mitogenic and cell survival activities and are involved in a variety of biological processes including embryonic development，cell growth，morphogenesis，tissue repair，tumor growth and invasion. FGF-23 inhibits renal tubular phosphate transport. The FGF-23 gene was identified by its mutations associated with autosomal dominant hypophosphatemic rickets （ADHR），an inherited phosphate wasting disorder. Abnormally high level expression of FGF-23 was found in oncogenic hypophosphatemic osteomalacia （OHO），a phenotypically similar disease caused by abnormal phosphate metabolism. FGF-23 mutations have also been shown to cause familial tumoral calcinosis with hyperphosphatemia.
