PIK3R1 and cancer: Additionally, our results showed that low expression of PIK3R1 was correlated with the poor prognosis of patients with various cancer types, for instance, BRCA, which was consistent with previous study26, and HNSC, STAD, UCEC, LUAD, etc. Noteworthily, although we failed to observe the statistical difference of PIK3R1 between LIHC and normal tissues, we found PIK3R1 underexpression was correlated to poor OS, RFS, PFS, DSS in LIHC cases through Kaplan-Meier plotter database.