As a mechanism for periodontitis to induce atherosclerosis, it is suggested that the heat shock protein (HSP) of P. gingivalis serves as an antigen peptide pathogen that provides an epitope in promoting atherosclerotic autoimmunity, thereby activating T and B cells by triggering inflammatory responses during early stage atherosclerosis (Choi et al., 2011). This evidence concerns the gene HSP90B2P and periodontitis.