library_construction_protocol: GFP+ GBMs were macrodissected, papain-based and mechanically dissociated. A debris removal step was performed, and blood cells were removed using a blood lysis buffer. Cells were labeled with eBiosciences Fixable Viability Dye Fluor 450 sorted using the MoFlo Astrios cell sorter. Live cells were collected, centrifuged and resuspended in a final volume of HBSS-0,1%BSA to get a 1200 cells/µL solution. Libraries were prepared according to Illumina's instructions accompanying the Chromium Next GEM Single Cell 3ʹ Reagent Kits v3.1. Libraries were sequenced on the Chromium Controller (10X Genomics) following the manufacturer's protocols. single cell RNAseq 10X 3' v3 kit