HSPD1 and periodontitis: Furthermore, mucosal administration of related autoantigens is an effective way to lessen autoimmune diseases by inducing an unresponsive state of tolerance (Calder et al., 2006) because Hsp60 (GroEL) from P. gingivalis can trigger a connection between atherosclerosis and periodontitis (Choi et al., 2004; Choi et al., 2011).