MTOR and cancer: Our studies [11–13] and others [26, 43, 44] have demonstrated that PI3K-AKT-mTOR signaling is often hyper-activated in RCC, which positively contributes to multiple key cancerous behaviors, including uncontrolled cell survival, proliferation, migration, as well as apoptosis resistance, cancer metastasis and angiogenesis [26, 43, 44].