Our strategy (i) is less expensive to produce, (ii) is specific to the tumor cells (sparing the residual CD5- B lymphocytes and T cells of the patient), (iii) could be broadly used in CLL patients with high-risk genetic lesions, (iv) is not down-regulated by the lymphocyte microenvironment, and (v) does not provoke apparent anemia or toxicity in a CLL mouse model. This evidence concerns the gene CD5 and anemia (phenotype).