Under a Creative Commons license open access Referred to by Immunity, Volume 56, Issue 11, 14 November 2023, Pages 2469-2471 James L. Ross, Dolores Hambardzumyan Keywords tumor microenvironment tumor immune microenvironment glioma glioblastoma brain metastasis tumor immunology neutrophil-to-lymphocyte ratio immune suppression angiogenesis myeloid niche TNF-alpha Introduction Central nervous system tumors comprise primary and metastatic malignancies and often confer a poor prognosis.