ACTA2 and glioma: We observed that in GEMM of gliomas, oncostreams are formed by GFP+ tumor cells, and are enriched in other tumor microenvironment cells such as ACTA2+ mesenchymal cells, IBA1+, and CD68+ tumor associated microglia/macrophages cells, Nestin+ cells and GFAP+ glial derived cells (Fig. 1E–G and Supplementary Fig. 2A–D).