In line with this, we observed a reserve correlation of p65 activation (p‐p65 or nuclear p65) or IκBα phosphorylation with CTR1 expression in breast cancer cells (Figure S7S, Supporting Information), and breast cancer tissues (Figure 4P), indicating a potential negative regulation of CTR1 by the NF‐κB pathway. Here, SLC31A1 is linked to breast cancer.