GFAP and neoplasm: We selected the clustering resolution that separated the cells into six clusters (Fig. 1e): one cluster of lymphoid cells based off expression of CD3D, two clusters of myeloid cells based off expression of CD14 and FCGR3A/CD16, one cluster of stressed/dying cells (dominated by long non-coding RNAs like MALAT1, NEAT1, and heat shock proteins (HSPs)), one cluster of tumor or normal brain cells based off expression of GFAP and SOX2, and one cluster of cells that had too few reads to accurately classify (Supp.