EPO and anemia (phenotype): In CKD patients receiving dialysis, for example, relatively fewer children than adults achieve target hemoglobin (Hb) [9], and in 1,724 children and adolescents in the North American Pediatric Renal Transplant Cooperative Study database, of whom 31 % had anemia (hematocrit <30 %), only 13 % were receiving erythropoietin [4].