Fig. 1: USP18 is highly expressed in glioma cells, particularly in GSCs, and is associated with poor outcomes in glioma patients.

A Single-cell RNA sequencing analysis of glioma subpopulations (Synapse dataset ID: syn22257780). Expression levels of stem cell markers (e.g., CD44, Nestin and SOX2) across clusters were visualised using the Seurat R package. B Correlations between the expression levels of different gene modules and the proportions of cell subpopulations in GBM tissues. C Overlap of the deubiquitinating enzyme family with the MEblack gene module. D The expression levels of USP18 in glioma cells and glioma stem cells were analysed in GSE124145. E Comparison of the expression levels of USP18 between glioma tissues and normal brain tissues in the GSE4290 dataset. F Pan-cancer analysis of USP18 expression (TIMER2.0 database). Tumour vs. normal tissue comparisons were performed using the Wilcoxon rank-sum test. G Single-cell transcriptomic distribution of USP18 across cell types in glioma (TISCH database; 15 datasets). H Kaplan–Meier survival curves for glioma patients stratified by USP18 expression (TCGA cohort; log-rank test). I USP18 protein expression in glioma tissues (WHO grades II–IV) and normal brain tissues was measured by Western blotting. J, K Representative IHC images of USP18 in gliomas with different histological grades and NBTs, along with the corresponding statistical results. L Kaplan–Meier survival analysis of 90 collected glioma samples on the basis of the USP18 IHC scores. M, N USP18 mRNA (qPCR) and protein (Western blot) levels in glioma cell lines (U87, LN229, U251, T98, U118, and A172) versus normal astrocytes (NHA, SVGP12). All the results are presented as the means ± SDs (from three independent experiments). *P < 0.05, **P < 0.01, ***P < 0.001.