CD8A and glioblastoma: Since a positive correlation between CD4+ and CD8+ cells was present in GBM, we investigated their complementary role in patients’ outcomes; hence, GBM patients have been divided into four different subgroups according to the number of CD4+ and CD8+ cells as follows: CD4H/CD8H, CD4H/CD8L, CD4L/CD8H, and CD4L/CD8L.