We performed DNA sequencing to identify coding variants in 12 genes recurrently mutated in GBM (BRAF, EGFR, IDH1, IDH2, NF1, NRAS, PDGFRA, PIK3CA, PIK3R1, PTEN, RB1, TP53) [13] (Fig. 2b, Additional file 2: Table S2). The gene discussed is PIK3R1; the disease is glioblastoma.