MTOR and neoplasm: Inhibitors of vascular endothelial growth factor receptor (VEGFR, e.g., sunitinib and axitinib) and mTOR (e.g., everolimus) exhibit anti-tumor activity in ccRCCs [39–41], largely due to the activation of angiogenesis and the PI3K-AKT-mTOR signaling [42–45].