ATM and B-cell chronic lymphocytic leukemia: Deletion of the long arm of chromosome 11 is seen in 5-20% of CLL patients6,25,26.The minimal deleted region including 11q22 ATM gene has been studied frequently in cases of CLL with del(11q), but it has been detected in 8-30% of 11q-patients27.This finding shows that other genes have important role in 11q deletions.