ABSTRACT
I. INTRODUCTION B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the relentless accumula tion of small, resting, long-lived B cells, that typically coexpress on the surface faint levels of immunoglobulins (Ig) and the CD5 molecule. CD5 is also present on the membrane of mantle zone lymphoma (MZL) cells, but differs from CLL cells in any other respect.
