This finding may support the role of other members of the TLR family, such as TLR3, TLR4, TLR7, TLR8, and TLR9, which promote Th1 responses against intracellular pathogens directed by cell-mediated immunity, and induce B cells to release high levels of IgG and IgA antibodies that drive phagocytic activation and defense against intracellular pathogens such as influenza [20]. Here, TLR4 is linked to influenza.