MTOR and breast cancer: Lapatinib has been shown to inhibit the HER2 downstream signaling pathways RAF/MEK/ERK (ERK cascade) and PI3K/AKT/mTOR and lead to up-regulations of BIM (BCL-2–interacting mediator of cell death) and BID (BCL-2 antagonist of cell death) in HER2-overexpressed breast cancer cells [38].