The activation of MAPK p38 in influenza virus single [52] or co-infections with S. pneumoniae [53] or S. aureus [54] was shown to play an essential role in the production of cytokines, such as IFNβ, IL-1β, tumor necrosis factor α (TNFα) and IL-6, in vitro and in vivo [54]. This evidence concerns the gene TNF and coinfection.