A recently published randomized clinical trial in stage 3b/4 CKD patients, the CKD Optimal Management with BInders and NicotinamidE (COMBINE) study, hypothesized that lowering phosphate level in early CKD prevents rising level of FGF23 and with that FGF23-associated morbidity and mortality (Figure 3). This evidence concerns the gene FGF23 and chronic kidney disease.