ISG15 and glioblastoma: Survival analysis of TCGA-GBM data was carried out, and 10 genes (CCL2, UPP1, F2R, ITGA5, SFN, IRS1, CXCL8, MAP1LC3A, MET, and ISG15) out of 138 genes had significant survival differences between high- and low-expression groups.