As the severe periodontitis induced by the ligature placement resulted in very high serum level of TNF-α in mice and as many previous studies have indicated the important role of TNF-α on the development of atherosclerosis in mice23,24, we studied the mechanisms of periodontitis-induced atherosclerosis by investigating the role of TNF-α on various events of atherogenesis in vitro setting. This evidence concerns the gene TNF and periodontitis.