FGF23 and anemia (phenotype): It is now known that in CKD, there is altered cleavage of FGF23 in response to anemia, erythropoietin (EPO), and inflammation.(41) Throughout the course of CKD, cFGF23 levels typically decrease, resulting in a large pool of active, intact FGF23.(42) In this study, we observed increased cFGF23 in the serum of all CKD animals, increasing further with GKT with or without KP, but no effect of KP alone.