A time-course study indicated that TNF-α acts as a priming factor to increase HDGF release from hepatoma cells during H. p. infection, and HDGF is also known as an intermediator that amplifies and maintains downstream COX-2/TNF-α signaling through the activation of nuclear factor kappa B (NF-κB) [96,97]. This evidence concerns the gene HDGF and hepatocellular carcinoma.