MTOR and breast cancer: The Akt/mTOR pathway has been shown to be frequently activated in various malignant tumors, including breast cancer, urothelial carcinoma, ovarian cancer, pancreatic neuroendocrine tumors, human medulloblastoma, melanoma, endometrial cancer and hepatocellular carcinoma; therefore, this pathway represents a possible therapeutic target in many cancers [23]–[30].