TLR4 and neoplasm: For example, certain microbes with anti-tumor effects, such as Bacteroides thetaiotaomicron and B. fragilis can activate dendritic cells through Toll-like receptor (TLR)-4 signaling and promote Th1 and cytotoxic CD8+ T cell responses helpful for the tumor immunosurveillance and eradication (Vetizou et al., 2015).