CD4 and meningioma: In addition, we evaluated several immune cell markers, including CD4, CD8, CD20, CD68, CD163, PD-1, PD-L1, and FOXP3 in meningioma samples (Figures 4A–H), and found that the lymphocyte infiltrates in the meningioma tissue was comprised predominantly of T cells with infrequent B cells (Table 3).