Further, murine studies have corroborated the findings of Greisman et al., (1963), who found that challenge with lipopolysaccharide (LPS) after infection did not lead to the production of pro-inflammatory cytokines such as Tumor Necrosis Factor α (TNFα) in mouse cell lines nor in vivo (Telepnev et al., 2003, 2005; Bosio, 2011). Here, TNF is linked to infection.