A protein which stores iron. Low levels of ferritin in a blood sample point to iron deficiency, even in a person who does not have signs of ANAEMIA. Raised levels of ferritin are found in many illnesses where there is inflammation involved, in liver disease, chronic alcohol consumption, kidney failure and some cancers. It may be present also in patients who have received numerous blood transfusions, for example because of THALASSAEMIA. Where none of these is present, the person concerned requires investigation for hereditary HAEMOCHROMATOSIS in which excess iron is absorbed from ingested food.