CD4 and cancer: Furthermore, TA-MSCs release CCL5, which can bind to CCR5 receptors on breast cancer cells, enhancing CXCL12 expression within stimulated cancer cells and facilitating the migration and infiltration of TAMs and MDSCs.521 The interaction between TA-MSCs and immune cells, particularly CD4+ T cells, is a significant aspect that warrants attention.522 TA-MSCs demonstrate adaptability and responsiveness to signals from CD4+ T cells, which, in turn, promote tumor progression.