CD8A and central nervous system cancer: However, this capacity to restore T cell functionality was suppressed in the presence of glioma supernatants and in the presence of U87 glioma cells, although the CD8+ IFN-γ T cells demonstrated the best recovery with SCH5826, especially in the presence of glioma supernatant (Figure 7), indicating that the immune effector cells are refractory to being immunologically reinvigorated in the presence of glioma.