TFRC and cancer: In particular, key proteins related to iron and to the growth, proliferation and metastasis of cancer cells include ribonucleotide reductase, which plays a major role in DNA synthesis; transferrin for iron transport in the blood; transferrin receptors for regulating iron intake intracellularly; ferritin for intracellular iron storage and utilization; and many others [8,9,10,22,23,24].