However, recent studies provided strong evidence for the participation of NK cells in the innate immune response to bacterial infections via the production of pro-inflammatory cytokines, such as interferon gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) (Souza-Fonseca-Guimaraes et al., 2012; Adib-Conquy et al., 2014). Here, TNF is linked to bacterial infectious disease.