The presence of CD8+ TEM Gzmk+ cells in aged VaD brains raises intriguing questions regarding their precise contributions to neuropathology especially given recent findings implicating this cell type in autoimmune diseases.56–59,59,110–112 In contrast the aging brain, these diseases all possess autoimmune or foreign body components (i.e., allogeneic transplant or infection). This evidence concerns the gene CD8A and autoimmune disease.