TFRC and hemoglobinopathy: Of 76 children with elevated sTfR, 22 had low inflammation-adjusted ferritin and 19 had malaria, a hemoglobinopathy (HbSS) or homozygous α+thalassemia, and/or elevated reticulocytes (i.e., causes or evidence of increased erythropoiesis); 3 children had results consistent with both iron deficiency (as assessed by adjusted ferritin) and increased erythropoiesis (as assessed by reticulocyte number).