Indeed, we previously demonstrated that correcting anemia in a CKD model using recombinant EPO, FG-4592, and BAY85-3934 reduced FGF23.25,26 In clinical studies in ADHR patients, iron therapy suppressed FGF23 expression and improved clinical disease manifestations.19 However, whether this was due to direct actions of FGF23 from the osteocyte was unclear. This evidence concerns the gene FGF23 and anemia.