LCK and B-cell chronic lymphocytic leukemia: We used this method to determine Lck expression in the malignant cells from 40 cases of CLL (Supplementary Table 1), and found a range of expression from very low (31.5 pg Lck/10 μg total cellular protein) to very high (235 pg Lck/10 μg total cellular protein) that was unrelated to IGHV mutation status.