OLFML3 and glioblastoma: After filtering out differentially expressed mRNAs with an expression fold change of less than two in the RNA-seq data and genes whose expression was not elevated in GBM tumor tissues compared with the corresponding normal tissues in the TCGA database, EIF4EP3, GLDC, ITGA10, CITED4 and OLFML3 were selected for further analysis (Fig. 6C).