TF and cancer: The transferrin receptor (TfnR) has been used extensively as a drug delivery system, since it binds and internalizes iron-bound transferrin (Tfn) to deliver iron into cells [11], [12] Given that the TfnR is over-expressed in tumors compared to normal cells [12], Tfn has been used as a carrier for anti-cancer drugs or other therapeutic agents to enhance targeting specificity towards neoplasic tissues [3], [12], [13].