On the other hand, as previouslydescribed by other authors, FGF-23 levels increase with the progression of CKD.5 Likewise, there was a positive associationbetween FGF-23 with P and PTH, according to Lavi-Moshayoff et al., who demonstratedthat PTH enhances FGF-23.6 gene transcription.The relationship between FGF-23 and ferritin was inverse to that reported in theliterature.7 However, experimental studieshave shown that both iron deficiency and administration of some iron-rich compoundscan stimulate the synthesis of FGF-23.8 The gene discussed is FGF23; the disease is Iron deficiency anemia.