Our results indicated that the MDM inhibitors (e.g., RITA) and inhibitors of TGFB or TGFBR (e.g., SB525334) used with doxorubicin showed synergistic interactions in drug combination assays, and that the administration of MDM inhibitors or TGF-β/TGF-βR inhibitors alongside doxorubicin may have the potential to improve the survival rate of breast cancer patients. Here, TGFB1 is linked to breast cancer.