TFRC and Iron deficiency anemia: Low levels of ferritin and high levels of sTfR signify deficiency of iron stores in the absence of inflammation.20, 21 Mean ferritin concentration was lower in children with deficiency of iron stores (1.9 (SD 0.7) μg/l) than in those with no deficiency (2.8 (SD 0.5) μg/l, p = 0.05), or with functional iron deficiency (2.6 (SD 0.6) μg/l, p<0.001).