These findings provide evidence that APC/C targeting using proTAME induces a metaphase arrest in DLBCL and MCL cells, resulting in the accumulation of cyclin B1 and a prolonged activation of Cdk1, followed by phosphorylation of Bcl-2 and Bcl-xL and eventually cell death. The gene discussed is BCL2L1; the disease is mantle cell lymphoma.