Blocking HMGB1/TLR4 signalling pathway may protect cardiomyocytes from DCs mediated cardiomyocytes hypoxia/reoxygenation injury, the co‐culture experiment provides an important theoretical basis for the role of HMGB1/TLR4 signalling pathway in the pathogenesis of DCs in the pathogenesis of MI/RI. The gene discussed is HMGB1; the disease is myocardial infarction.