TNF and periodontal disorder: In the LPS-injected gingival tissues, the positive correlation between inflammation and increased levels of SOCS3 mRNA and protein is consistent with the literature showing that the expression of SOCS is induced by LPS and inflammatory cytokines such as IL-6, IFN-γ, and TNF-α, [7, 18, 19] which are produced in response to intense antigenic challenge in periodontal disease [20–22].