Previous reports have identified metformin playing a role in activating AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) signaling pathway, which is important in regulating cancer cell survival, proliferation and apoptosis, as well as the process of epithelial-to-mesenchymal cells transition (EMT) phenotype [12–14]. The gene discussed is MTOR; the disease is cancer.