In all patients of the first group (patients with a high activity of the inflammatory process in the aneurysm wall), in the lumen of the vasa vasorum vein and among the attached cells, there were CD3, CD4, and CD8 T cells (Figure 1C–H and Figure 2C–F) (usually one or two T cells were attached in one vein of the vasa vasorum). Here, CD4 is linked to aneurysm.