BCL2L1 and glioblastoma: Cingöz and his coworkers showed that TRAIL-mediated apoptosis in glioblastoma (GBM) cell lines can be promoted following combination therapy with proteasome inhibitor bortezomib and TRAIL, evidently by down-regulating Bcl-2 or Bcl-xL, suggesting a role for these anti-apoptotic proteins in inducing resistance to apoptosis-inducing cytokines, in particular, TRAIL (40).