Although the down-regulation of either Bcl-xL or Mcl-1 remains ineffective, we showed that the concomitant inhibition of these proteins with siRNA was sufficient to induce massive cell death, highlighting the pivotal role these anti-apoptotic proteins play in chemoresistant ovarian carcinoma and mesothelioma [5]. The gene discussed is BCL2L1; the disease is ovarian carcinoma.