PIK3R1 and glioblastoma: Analysis of expression profiles showed that the expression of ARIDIA, CIC, EGFR, IDH1, KAT6B, PIK3R1 and TP53 was significantly higher in LGG and GBM patients compared with normal samples (p < 0.001 for all the genes) and FLG expression in LGG was significantly higher than that of normal samples (p < 0.001; Figure S4A).