ATM and B-cell chronic lymphocytic leukemia: Despite that aberrant methylation of the ATM promoter has been reported in various cancer types such as breast cancer,23 head and neck cancer,24 non-small-cell lung cancer25 and in primary gastric lymphoma,26 one study in CLL showed no apparent methylation was detected in ATM promoter region.27 In concordance with this study, our methylation analysis in four CLL samples, which lost ATM function in the absence of a mutation, did not detect any promoter hypermethylation.