MTOR and breast cancer: Some of the targeted therapies widely used in breast cancer treatment include mAbs such as trastuzumab and pertuzumab; tyrosine kinase inhibitors such as lapatinib; cyclin-dependent kinase inhibitors such as palbociclib; mammalian target of rapamycin (mTOR) inhibitors such as everolimus; and poly-ADP-ribose polymerase (PARP) inhibitors [5].