CD8A and myeloid sarcoma: Furthermore, a subpopulation of T cells expresses the surface marker CD20 at low levels (defined as CD3+CD20dim); this population represents about 7% of the total T-cell population and includes both CD4+ and CD8+ T lymphocytes [106], but it is still unknown whether its depletion might contribute to the clinical effectiveness of anti-CD20 mAbs in MS and other autoimmune diseases.