TLR2 and cancer: Intestinal microbiota may produce carcinogenesis by genotoxicity, such as through colibactin production, activation of Toll-like receptor 2 (TLR2)/TLR4 signaling and inhibition of apoptosis, suppression of host immunity response, and/or production of metabolites (e.g., lactic acid) that increase cancer progression [5,60,62,64].