TFRC and Iron deficiency anemia: We addressed the question to which extend the classical biomarkers such as ferritin, soluble transferrin receptor, total iron-binding capacity, transferrin saturation, hepcidin, and serum iron can be used for the diagnosis of iron deficiency anemia, but also ZnPP which is a less frequently used biomarker that, however, is less affected by the severity of inflammation compared to the others [14].