The peptide 19 from P. gingivalis HSP60 (Pep19) has been studied as one of the dominant peptides, from which, the epitope-specific immune response to subdominant epitopes could be sequentially diversified towards autoimmune responses directed against human neoepitope in periodontal disease induced by P. gingivalis and in autoimmunity (91). Here, HSPD1 is linked to periodontal disorder.