MTOR and breast cancer: Studies have shown that PI3K/AKT/mTOR pathway played critical roles in the development of cancer,49 which can be abnormally activated in a variety of tumours and promote the growth, invasion, metastasis and EMT of tumours, such as ovarian cancer, breast cancer, gastric cancer, lung cancer, and head and neck squamous cell carcinoma.50, 51, 52, 53, 54