GX15-070 displaces Bak from Mcl-1 and Bcl-XL. MCL cell lines were treated for 5 hours with 5 μM (Jeko and Granta-519) or 0.5 μM (UPN-1) GX15-070. Mcl-1 and Bcl-XL immunoprecipitations were performed as described in “Patients, materials, and methods.” Immunoprecipitated (IP; bound) and nonimmunoprecipitated (unbound) fractions were analyzed by Western blotting for Bak, Mcl-1 and Bcl-XL proteins. Western blot (WB) images are representative results from 3 independent experiments.