MTOR and renal cell carcinoma: The mTOR signaling pathway is often activated in RCC, and higher levels of the phosphorylation status of the pathway proteins (mTOR, 4EBP and S6K) have been reported to be associated with poorer prognosis in ccRCC patients (HR = 0.9, 1.5 and 1.5 for OS and HR = 0.9, 2.7 and 2.6 for PFS, respectively)33.