As the total numbers of cardiac MDSC and S100A8/9-expressing MDSC as well as cardiac IL1-ß and IL-6 mRNA levels and inflammatory cells were significantly higher in ABY/SnJ mice than in resistant C57BL/6 mice, we concentrated on the role of MDSC in the outcome of myocarditis in permissive ABY/SnJ mice. The gene discussed is S100A8; the disease is myocarditis.