For example, downregulation of TLR5 in triple-negative breast cancer (TNBC) increased tumor invasiveness and epithelial–mesenchymal transition (EMT) expression and promoted TNBC metastasis [32, 33]; TLR9 agonist CpG oligonucleotide was widely shown to have an anti-tumor effect by stimulating local immunity [34, 35]. Here, TLR9 is linked to triple-negative breast carcinoma.