ZAP70 and B-cell chronic lymphocytic leukemia: Decline of 50% or more between sequential samples and/or value of ≤ 0.005 at the initial observation were noted in serial samples collected from 16 patients that do not have CLL cells with high expression of ZAP-70 and unmutated IGHV, whereas only in 5 patients sequential samples were lacking in properties while CLL cells expressed high ZAP-70 and unmutated IGHV (Table 1).