As CMS1 and CMS4 are thought to represent tumor-immune inhibitory and stimulatory environments, respectively, we hypothesized that F. periodonticum and B. fragilis would stimulate anti-tumor cytokines (IFN-γ, IL-12 IL-18), and decrease tumor-promoting cytokines (IL-1β and IL-6)26,27, while the opposite effect may be seen with P. asaccharolytica. This evidence concerns the gene IFNG and neoplasm.