Unsupervised clustering of CD133+ cells vs. CD133- cell gene expression signature from each tumour sample show 2 main GBM groups. To molecularly characterize glioblastoma stem cells of GBM tumours, we compared the gene expression profiles of purified CD133+ cells from GBM patients versus CD133-cells from each patient. Each gene (identified at right) is represented by a single row of coloured boxes; each patient is represented by one single column. Data are displayed by a colour code where red indicates over-expression in CD133+ fraction versus CD133-cells. A group of genes over-expressed for almost all samples are grouped in the bottom. SOTArray tool from GEPAS Release v3.1, let us to classify CD133+ vs. CD133- cells from each tumour in 2 mainly groups: G9, G11 and the rest.