CD200 and B-cell chronic lymphocytic leukemia: As mentioned above, an anti-CD200 antibody led to the disruption of T-cell suppression as measured in autologous MLCs using CD40 ligand (CD40L)-stimulated CLL cells as antigen-presenting cells (APCs) [40], a mechanism inferred by Wong et al. in studies on NOD.SCID mice with CLL cells [23].