PIK3CB and nonpapillary renal cell carcinoma: Specifically, increased expression levels of PTEN (P < 0.001), PIK3CA (P < 0.001), PIK3CB (P < 0.001), PIK3CG (P = 0.004), AKT3 (P < 0.001) and mTOR (P = 0.001) were correlated with a significantly improved OS in 528 patients with ccRCC, whereas the overexpression of PIK3CD mRNA (P = 0.048) was significantly correlated with poor OS.