In this prospective study, we investigated the role of and Chlamydia pneumoniae (CP), Chlamydia heat shock protein (Ch-hsp) 60 and a possible intermediate role of human heat shock protein (h-hsp) 60 antibodies in the development of secondary cardiovascular events in patients with coronary heart disease (CHD) under special consideration of diabetes mellitus. The gene discussed is CP; the disease is diabetes mellitus.