For example, treatment of HER-positive breast cancer cells with depletion of Atg5, Atg7, or beclin1 resulted in enhanced effectiveness of tamoxifen or the combination therapy of 3-MA, as an autophagy inhibitor, and trastuzumab, as a chemotherapeutic drug, increasing the effectiveness of chemotherapy in HER2-positive breast cancer cells as compared to monotherapy (71). Here, BECN1 is linked to breast cancer.