Ferritin is a protein of 450 kDa consisting of 24 subunits that is present in every cell type. Invertebrates, these subunits are both the light (L) and the heavy (H) type with an apparent molecular weight of 19 kDA or 21 kDA respectively. The ferritin found in cancer cells was found to consist mainly of H chains. The heavy chain of Ferritin also possesses ferroxidase activity, this involves the conversion of iron from the ferrous (Fe2+) to ferric (Fe 3+) forms [1][2][3][4].

If the ferritin level is low, there is a risk for lack of iron, which could lead to anemia. If ferritin is high, there is iron in excess or else there is an acute inflammatory reaction in which ferritin is mobilized without iron excess. For example, ferritins may be high in infection without signaling body iron overload. Ferritin is also used as a marker for iron overload disorders, such as hemochromatosis or hemosiderosis. Recent research has shown that H-Ferritin from melanoma cells may suppress immune responses [5][6][7].