2. A diagnosis of Chronic Lymphocytic Leukemia(CLL) which is CD5/CD19/CD23 positive, confirmed by peripheral blood immunophenotyping and/or lymph node biopsy and immunophenotyping and/or bone marrow biopsy and immunophenotyping. CD23-negative CLL cases are eligible, however additional diagnostic confirmation should include absence of Cyclin D1 rearrangement [t(11;14)] as determined by standard laboratory methods (such as fluorescent in situ hybridization).