Over-expression of TLR-9 has been observed in several types of cancer, both in established in vitro cells lines and in human cancer samples, including breast cancer, gastric cancer, hepatocellular carcinoma, cervical squamous cell carcinoma, glioma, prostate cancer, colorectal cancer and neuroblastoma [21,22,44]. This evidence concerns the gene TLR9 and hepatocellular carcinoma.