PTEN and nonpapillary renal cell carcinoma: The expression levels of PTEN, AKT and p-AKT (S473) were positively correlated with both tumor stages (P < 0.001; P = 0.045 and P < 0.001, respectively) and tumor grades ( P < 0.001; P < 0.001 and P < 0.001, respectively) in patients with ccRCC, which is consistent with previous studies (Han et al., 2017).