TNF and periodontitis: A search for potential markers of periodontitis onset or progression resulted in many potential candidates for such agent—among others matrix metalloproteinase (MMP)-8, IL-1, IL-6, tumor necrosis factor (TNF)-α, PGE2 (Barros et al. 2016; Chen et al. 2019; He et al. 2018; Isola 2021).