IRF1 and glioblastoma: To identify potential miR-203a target genes we performed microarray analysis on MT330 and SJG2 GBM cells with enforced miR-203a expression, and found the spontaneous induction of IFN-stimulated genes (ISGs), including IFI6, IFT20, IRF1, ISG15, ISG20, and MX1 (Supplementary Table 1), which was surprising as miRNAs typically downregulate gene expression and these ISGs did not have identifiable miR-203a binding sites in their 3'UTRs.