CD4 and glioblastoma: In the PBMC, GBM patients and normal donors showed similar ratios of CD4 to CD8 T cells (range 1.2-2.1); however, GBM patients’ PBMC contained substantially fewer peripheral T cells overall, with CD4 at 10% and 33.6%, and CD8 at 5.8% and 17.5%, in GBM versus ND respectively (Supplementary Figure S3C).