TLR2 and colorectal carcinoma: In vitro, enterotoxins produced by B. fragilis have been associated with DNA damage and genomic instability [64], while, in mice, Peptostreptococcus anaerobius, another CRC-enriched species, was shown to interact with TLR2/4 receptors on host cells to induce ROS production, increasing cholesterol biosynthesis and activating pro-oncogenic factors and CRC-promoting pathways [65].