It is also worth noting that microarray-based transcriptomics analysis of GBM subtype tumours, freshly derived tumour cells from these cells and the respective orthotropic xenografts obtained from the freshly derived tumour cells, all showed similar high expression of SUMO2 [Stringer et al., GEO-GSE118793] [41](Fig. 3A–C and Additional file 4: Table S31). This evidence concerns the gene SUMO2 and glioblastoma.