PIK3CB and nonpapillary renal cell carcinoma: Then Oncomine database (U133A/B microarray, 10 ccRCC and 10 matched normal kidney specimens) was used to validate their differential expression (Table S2), which demonstrated that most of the PI3K/AKT/mTOR members were not significantly changed between ccRCC and normal specimens (P > 0.05) except PTEN (1.77-fold increase in ccRCC, P < 0.001), PIK3CA (1.56-fold increase, P = 0.010) and AKT1 (1.27-fold increase, P = 0.005).