CD4 and breast cancer: During the breast cancer progression, the proportion of CD3+CD4+ T cells and CD3+CD8+ T cells in peripheral blood, spleens and axillary lymph nodes were significantly decreased (Figure 6A–6B), and the decreased proportion of CD3+CD4+ T cells and CD3+CD8+ T cells were negatively relative to the increased CXCR2+ MDSCs in peripheral blood (Figure 6C–6D).