CD28 and glioblastoma: Overall, expression of specific immune checkpoint genes and many receptor-ligand pairs implicated in GBM malignancy and immune suppression are increased in M-H GBMs, including CD276 {Zhang, 2018 #380}, CSF1R:CSF1 {Pyonteck, 2013 #381}, CD70:CD27 {Wischhusen, 2002 #382}{Jin, 2018 #383},TNFRSF9:TNFSF9 {Freeman, 2020 #384}{Cho, 2021 #385}, CTLA4:CD80/86, and CD28:CD80/CD86 {Guan, 2021 #386} (Fig. 3B).