ZAP70 and B-cell chronic lymphocytic leukemia: Moreover, MELK overexpression was also found in chronic lymphocytic leukemia (CLL) cells, and positively correlated with advanced stage, higher WBC count, increased β2-MG level, elevated LDH, unmutated IGHV, deletion of 17p13, positive ZAP-70 and inferior prognosis of CLL patients (14).