PTEN and nonpapillary renal cell carcinoma: In a large cohort of 419 primary ccRCC patients, aberrantly expressed components of the PI3K signaling cascade (e.g., PTEN, PI3K, p-AKT, mTOR, p-mTOR, p-S6, and p-4EBP1 proteins) exhibited aggressive pathological features and caused adverse survival (Darwish et al., 2013).