A 58-year-old Indian male presents with painless lymphadenopathy and splenomegaly. Lymph node biopsy shows follicular lymphoma with t(14;18) translocation. The structure marked **A** in the diagram (Bcl-2 family proteins) is overexpressed due to placement of the BCL2 gene under the control of the immunoglobulin heavy chain promoter. Which of the following best explains the pathogenic consequence of this translocation and the rationale for targeted therapy?