Everolimus, an mTOR inhibitor, approved for the management of HR-positive, postmenopausal breast cancer patients, in combination with an aromatase inhibitor (235) has also shown CNS penetration with activity against subependymal giant-cell astrocytomas associated with tuberous sclerosis (236), and ongoing studies are testing the activity of everolimus in BM. Here, MTOR is linked to breast cancer.