MTOR and breast cancer: Phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling is one of the most important intracellular pathways, has been found to be dysregulated almost in all human cancers, such as breast cancer, colorectal cancer, and hematologic malignancies, which can be considered as a master regulator for cancer, which regulates cell growth, motility, survival, metabolism, and angiogenesis [29].