More recently, however, persistently elevated FGF-23 levels were observed for prolonged periods of time after renal transplantation, and these have been associated with hypophosphatemia and low 1,25(OH)2D3 level independent of PTH.(61,62) It is plausible that patients who received a renal transplant and show persistently increased FGF-23 secretion despite a well-functioning kidney graft are at risk of accelerated deterioration of renal function just as nondiabetic CKD patients without a prior renal transplant(63); this is an important question that requires further study. This evidence concerns the gene FGF23 and hypophosphatemia.