TFRC and megaloblastic anemia: Its advantage, i.e., the fact that serum sTfR levels are not much affected by inflammation [59], does not outweigh its disadvantages such as lack of standardization assays [131], high cost, insufficient sensitivity in the early phases of ID [132], and increased sTfR levels in states of stimulated erythropoiesis such as hemolysis, megaloblastic anemia, thalassemia, and hypoxia [133].