The role of MBL in modulating immune responses has also been observed in Staphylococcus aureus infection. It was shown that MBL amplifies the host immune response during S. aureus infection by cooperating with Toll-like receptors 2 and 6 and augments the production of proinflammatory cytokines and chemokines [50] . The observation from our present study prompted us to further investigate whether MBL may also cooperate with other pattern-recognition receptors and thus further amplify the host response during influenza virus infection.