ICOSLG and glioblastoma: To estimate association of local protein expression with immune cell composition in the TME we correlated CXCL8 and ICOSLG expression in TCGA GBM data with matched immune cell type fractions estimated by Wang et al.17 Expression of CXCL8 and ICOSLG in the TCGA dataset revealed significant positive correlation with neutrophils, resting NK cells and activated CD4 memory T cells and negative correlation with resting CD4 memory T cells, resting mast cells, activated NK cells, and follicular helper T cells.