Antiapoptotic members of the Bcl-2 family such as Bcl-2 (B cell leukemia or lymphoma gene number 2), Bcl-xL (B cell lymphoma-extra large), or Mcl-1 (myeloid cell leukemia sequence 1) have first been identified in leukemia and lymphoma and are also frequently overexpressed in other types of neoplasia to inhibit apoptotic cell death during tumorigenesis. This evidence concerns the gene BCL2 and lymphoma.