PROM1 and glioblastoma: To address the relationship between surface-marker heterogeneity (phenotype) and clonality, an aspect that has not been widely studied in GBM, we have combined barcode labelling of GIC (enhanced blue fluorescent protein (EBFP) 2, T-Sapphire, Venus, and mOrange) with simultaneous capture of their surface-marker profiles for CD133, CD44, CD15, and A2B5.