PIK3CA and neoplasm: This PTEN/ARID4B/PIK3CA signature robustly stratified patients into those at high versus low risk for tumor recurrence (HR = 4.58, P = 0.006 in the GSE40272 dataset; HR = 3.23, P = 0.002 in the GSE21032 dataset; HR = 1.51, P = 0.025 in the TCGA dataset; Statistical analysis: log-rank test).