In DeFew cells, RNA interference of IBTKα caused the up-regulation of TNF, CRADD, CASP7, BNIP3 and BIRC3. The comparative analysis of representative number of CLL patients of Binet A, B and C stages and healthy donors revealed that the increased expression of IBTKα correlated with the decreased expression of TNFα in CLL progression, which was consistent with the enhanced expression of TNFα in DeFew cells upon IBTKα RNA interference. The gene discussed is TNF; the disease is B-cell chronic lymphocytic leukemia.