Whilst low hemoglobin levels represent the hallmark of anemia, other red cell indices such as mean corpuscular volume (MCV), red cell distribution width (RDW) and the red blood cell (RBC) count, in addition to other biochemical markers of iron status like serum ferritin and transferrin, provide further information on the pathophysiology and etiology of anemia. This evidence concerns the gene TF and anemia (phenotype).