The other mechanisms supporting iron supply in TC include the upregulation of lipocalin-2 (LCN2/NGAL), the innate immune response protein, which delivers iron cations to cancer cells, the downregulation of ferroportin (FPN1), which is responsible for efflux of iron ions from the cell as well as the upregulation of hepcidin, the secreted protein that promotes FPN1 degradation [91,147]. Here, SLC40A1 is linked to cancer.