In the example case of tumor LC26, abnormal phenotypes in glioblastoma cells included co-expression of astrocytic S100B and stem-like CD133 or co-expression of markers associated with different molecular subtypes of glioblastoma, such as mesenchymal (CD44) and classical (EGFR) (Figure 1—figure supplement 1; Verhaak et al., 2010). This evidence concerns the gene PROM1 and glioblastoma.