 The non- Hodgkin lymphomas NHL represent a heterogeneous group of malignancies. Under the rubric of lymphoma exist some of the fastest growing cancers known to science, Burketts lymphoma, lymphoblastic lymphomaleukemia, as well as some of the most indolent small lymphocytic lymphoma, follicular lymphoma, and marginal zone lymphoma. This remarkable diversity of biology imposes significant challenges. Researchers are seeking to understand the cell of origin and differentiate what are sometimes subtle differences between the related sub-types of disease; and to identify the best treatments for these subtypes, with the ever-increasing likelihood that new understanding of the molecular pathogenesis of these diseases will result in an increase in new drugs for specific target populations. 