PIK3R1 and cancer: lncRNAs NR_027340, MIR31HG, SOX2-OT and their correlated mRNAs ITGB1, HIF1A, DDIT4 were overexpressed in cancer tissues compared to adjacent non-neoplastic tissues (P<0.05), but there was no significant difference in the expressions of lncRNA NR_003949 and its correlated mRNA PIK3R1 (P > 0.05) (Fig 6).