TNF and periodontitis: Regarding periodontitis-associated atherosclerosis, a previous animal study found that ligature-induced periodontitis could activate PBMs and result in significant upregulation of proinflammatory genes including Tumor Necrosis Factor Alpha (TNFɑ) and IL-6 in PBMs to increase the adhesion of PBMs to the aortic endothelium, finally triggering the initiation of atherosclerosis [11].