CD8A and glioblastoma: In 2011, Yang I et al. compared immune cells’ microenvironment composition of glioblastoma and PAs showing that GBM specimens had a significantly higher percentage of perivascular CD8+ T cell, perivascular and intratumoral CD-56+ T cell (Natural Killer T cells), and macrophages while there was no difference between CD3+ and CD 20+ T cells [54].