TLR4 and colonic neoplasm: Lipopolysaccharides of the cell membrane of F. nucleatum can directly bind to the TLR4 of epithelial cells and thus activate the NF-κB signaling pathway, leading to the over-expression of various cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-8, IL-10, IL-12, and reactive oxygen species (ROS) production, similar to that observed in colonic cancer [67,68,69,70].