The administration of recombinant human erythropoietin (rhEPO) was associated with lower proportions of anemia, abnormal ferritin, and abnormal iron levels (63.27%, 26.53%, and 61.22%, respectively) compared to those not receiving rhEPO (79.66%, 35.59%, and 69.49%, respectively). This evidence concerns the gene EPO and anemia (phenotype).