TLR4 and neoplasm: Mucosal microbiota can influence carcinogenesis mechanistically by modulation of the host immune system (e. g., production of pro-inflammatory cytokines, which interact with Goblet and Paneth cells and compromise barrier function) and/or the innate immune system (e. g., tumor activation via NF-kB and STAT3 signaling pathways, including Toll-like receptor 4 (TLR4) activation and up regulation of the PTGS2 and EGFR signaling pathway) [6, 7].