BCL2 and B-cell chronic lymphocytic leukemia: Finally, by analysing genes that were differentially regulated in the presence of virus alone, drug alone or combination therapy in drug- and VSV-resistant chronic lymphocytic leukaemia (CLL) cells treated with obatoclax, a Bcl-2 inhibitor drug under clinical development, two core pathways involving apoptosis signalling and mTOR signalling were required to achieve efficacy following combination therapy.