2. CD22 expression must be detected on greater than 15% of the malignant cells by immunohistochemistry or greater than 80% by flow cytometry. The choice of whether to use flow cytometry or immunohistochemistry will be determined by what is the most easily available tissue sample in each patent. In general, immunohistochemistry will be used for lymph node biopsies, flow cytometry will be used for peripheral blood and bone marrow samples.