In our study on Helicobacter pylori (H. pylori) carcinogenesis, we discovered that tumor necrosis factor-α (TNF-α)-inducing protein (Tipα) of H. pylori is a carcinogenic factor that induces tumor promotion in vitro and in vivo (Suganuma et al. 2001, 2005). The gene discussed is TNF; the disease is neoplasm.