CD8A and glioblastoma: Consequently, a decreasedCD4+/CD8+ T cell ratio directly and strongly correlates with favorableclinical outcome.47 Another major componentof the tumor microenvironment consists of tumor-associated macrophages.In fact, up to 30% of the TME consists of these TAMs.48 Historically, TAMs have been linked to tumor progressionand poor outcomes in patients suffering from GBM.49 However, this perspective has proven to be oversimplified,as there are not only pro-tumorigenic M2 macrophages but also antitumorigenicM1 macrophages.