Assuming the prevalence of ESRD in Serbian adults of 0.07% (commonly with anemia of chronic disease), a post hoc power analysis showed that the recruited 126 patients with ESRD and 31 patients with sideropenic anemia (iron-deficient anemia) have power for identifying the associations (log-additive model of inheritance) 66% for TMPRSS6 A736V, 27% for HFE H63D, and 17% for HFE C282Y gene variants. This evidence concerns the gene TMPRSS6 and anemia.