Resistance of naturally occurring regulatory T cells toward oxidative stress: possible link with intracellular catecholamine content and implications for cancer therapy.

data are lacking. The published series treated with hyper-CVAD rituximab appear to relate to a heterogeneous group of patients of which only one-third had a MYC rearrangement.5 Using the current edition of the WHO classification, it is likely that most of the cases in the Manchester series would be placed in the category “B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell and Burkitt Lymphoma” rather than “Burkitt Lymphoma.”6 The justification for this new category is the recognition that these tumors are frequently refractory to chemotherapy and have short survival. As the data from LY10 shows, the accurate distinction between this group and Burkitt lymphoma is clearly important given the sharply contrasting responses to chemotherapy. The techniques used to make this distinction are likely to improve with the introduction of gene expression profiling and whole genome genotyping based on SNP arrays and array CGH. However, the key question will remain how to manage patients who are identified at presentation as having disease that is likely to be refractory to chemotherapy.