ZAP70 and B-cell chronic lymphocytic leukemia: Like IgVH status, overexpression of ZAP-70 in CLL cells is associated with aggressive disease; time to treatment is 2.6 years for ZAP-70+ patients compared with 8 years for ZAP-70− patients independent of Rai stage.3 Thus, ZAP-70 is a rationale target for therapy in CLL.