TLR5 and neoplasm: reported that an engineered attenuated S. typhimurium strain could successfully suppress the tumor growth and metastasis in murine colon and melanoma models through a secretion of Vibrio vulnificus flagellin B (FlaB) (Figure 6).[57] The underlying mechanism can be interpreted in the following manner: TLR4 signaling is a key to suppress tumor growth by inducing the activation and infiltration of immune cells mediated by FlaB‐secreting bacteria, whereas TLR5 signaling is capable of augmenting the host reactions.