BAK1 and cancer: Bcl-2 members with both proapoptotic (Bax, Bak, Bid, and Bim) and antiapoptotic (Bcl-2, Bcl-xL, and Bcl-W) situations are located in mitochondria.33 Thus, cancer cells may obtain resistance to apoptosis by Bcl-2 (antiapoptotic) overexpression or Bax (proapoptotic) downregulation.