ZAP70 and B-cell chronic lymphocytic leukemia: In this regard, specific chromosomal aberrations (i.e. 17p-, 11q- or +12), as well as the presence of an unmutated (UM) rather than mutated (M) status of immunoglobulin (IG) heavy chain variable (IGHV) genes, or expression levels for ZAP-70, CD38 and CD49d exceeding the value of an established threshold, have been reported to correlate with a poor clinical outcome in CLL [2-8].