MTOR and breast cancer: This review pays special attention to the increasing evidence that natural polyphenols can block migration and invasion of breast cancer cells through a series of molecular mechanisms, including the down-regulation of matrix metalloproteinases (MMPs) expression [18], the regulatory effects of epithelial-to-mesenchymal transition (EMT), the suppression of vascular endothelial growth factor (VEGF) signalling and cancer angiogenesis, the inhibition of nuclear factor-kappa B (NF-κB), and the mammalian targeting function of rapamycin (mTOR), as well as other signalling pathways.