Many of the genes found to be differentially expressed between IgM U-CLL and IgG M-CLL cells were previously reported to differ between U-CLL versus M-CLL (e.g., ZAP70, SEPT-10, BCL7A, AICDA, ADAM29, and CD86) (45, 46). Here, ZAP70 is linked to B-cell chronic lymphocytic leukemia.