MTOR and breast cancer: The clinical application of mTOR inhibitors has been successfully tested in treating advanced renal cell carcinoma, neuroendocrine tumors, and HER2-positive breast cancer.121 It can also ablate cisplatin-resistant salivary gland cancer stem cells, especially combined with platinum-based chemotherapy.321 Meanwhile, a new study also found that enhance mTOR-targeted cancer therapy can be enhanced by combining of other drugs such as mitoxantrone, an inhibitor of the eukaryotic elongation factor-2 kinase, which is overexpressed in cancer cells and is required for the survival of stressed cells.322