TNF and periodontitis: Thus, these nonhuman primate data were explored for determining interactions between the circadian pathway genes and expression of pro- (TNF, IL1B, IL6) and anti-inflammatory genes (IL4, IL10, TGFB1), as well as genes for products associated with soft tissue destruction or remodeling (CTSK, MMP2, MMP7, MMP9, MMP14) in the cross-sectional study of health and naturally-occurring periodontitis (Fig 3).