TNF and periodontitis: TNF-α and IL-6, which are known as tissue destruction mediators, function as pro-inflammatory cytokines, and their levels increase during inflammation.26 In GCP, these cytokines are thought to play an important role on the pathogenesis of the disease by stimulating bone resorption.26 In patients with severe periodontitis, corpuscles and adipocytes in the liver have been proposed as IL-6 sources.2,3 This information helps to understand the high level of GCF IL-6 in obese individuals.