Flow cytometry-based analysis of T-cell populations within tumors revealed a reduction in the number of CCR2+ cells, leading to a decrease in the percentage of CD4+FOXP3+ Treg cells, which are immunosuppressive, and an increase in activated CD8+ cytotoxic T cells expressing granzyme B. Thus, the findings of this study indicated that Ly6Chi monocytes expressing CCR2 play a crucial role in promoting tumor growth in response to MI, and their influx hinders the development of anti-tumor immune responses. The gene discussed is CD8A; the disease is neoplasm.