This research focuses on gene therapy as well as immunotherapy to target the breast cancer stem cells in breast cancer treatment. Breast cancer stem cells were isolated and proliferated from malignant breast tumors. About gene therapy, we used knockdown gene therapy to suppress the CD44 expression. CD44 holds an important role in stemness maintenance of breast cancer stem cells. CD44 down regulation makes breast cancer stem cells sensitize to anti-tumor drug (doxorubicin). So that combinatorial therapy of CD44 down-regulation and doxorubicin strongly suppressed the tumor growth in NOD/SCID...