It was also noteworthy that PTX@TF decreased the percentage of Treg cells by impairing their viabilities and tumor-suppressing functions rather than CD3+CD4+ helper T cells and CD3+CD8+ cytotoxic T cells (Figure 5F–H), which could further enable PTX to synergize with MMST to achieve a potent chemoimmunotherapeutic effect in the breast cancer. This evidence concerns the gene CD4 and breast cancer.