TLR4 and colorectal carcinoma: For instance, Escherichia coli NC101 promote invasive carcinoma in azoxymethane (AOM)-treated IL-10−/− mice through the polyketide synthase (pks) island and colibactin [9], while Fusobacterium nucleatum increases proliferation of CRC cells in vitro and tumorigenesis in mice by activating Toll-like Receptor 4 (TLR4) and nuclear factor-κB (NF-κB) signaling pathway and up-regulating expression of microRNA-21 [10].