Since TNFα, CRADD and CASP7 share the same pro-apoptotic pathway and are commonly up regulated in absence of IBTKα, it is feasible that, conversely, the enhanced expression of IBTKα in CLL cells could down regulate the expression of these pro-apoptotic genes, thus counteracting apoptosis. Here, CASP7 is linked to B-cell chronic lymphocytic leukemia.