To determine the origin of TDECs in primary patient GBM (p-GBM), we first co-stained for ETV2 with neural stem-like cell markers (Nestin, Vimentin, and CD133) or mature neural tumor cell makers (NeuN and GFAP) in cryosections of p-GBM autopsies. This evidence concerns the gene GFAP and glioblastoma.