CD40LG and B-cell chronic lymphocytic leukemia: To test gp41 reactivity of B-CLL purified IgMs, we rescued 5 IGHV1-69 B-CLL mAbs as hetero-hybridoma IgM paraproteins; CLL246, CLL526, CLL698, CLL821, and CLL1324 (all U-CLL) as described previously [28].