Our immunohistochemistry results further confirmed that, in the context of cancer, myocardial infarction thrombi exhibited significantly enhanced local infiltration of CD8+ T cells and Treg, as well as upregulation of PTX3, whereas CXCL8 and PD‐L1 levels remained largely unchanged, highlighting the complexity and diversity of the cancer–myocardial infarction microenvironment. This evidence concerns the gene CD8A and cancer.