Targeting CD71,41 acting as a transferrin receptor, would be of special interest, as CD71-overexpressing cancer cells are characterised with an increased iron uptake and, hence, should be more prone to prooxidant actions of ascorbate.42 Obviously, in HER2-expressing cancers, HER2 molecule itself might be targeted by the siRNA-antibody conjugate. Here, TFRC is linked to cancer.