In addition, TfR1 is involved in the regulation of the NF-kappa B (nuclear factor-kappa B) signalling pathway in cancer cells, and by interacting with IKK (inhibitor of NF-kappaB kinase), it activates the NF-kappa B signalling pathway to inhibit apoptosis, thereby promoting the survival rate of cancer cells (Fig. 2) [55]. Here, TFRC is linked to cancer.