Allogeneic stem cell transplantation (allo-SCT) is a potentially curative therapy for chronic myeloid leukemia and Philadelphia chromosome-positive (Ph(+ )) acute lymphoblastic leukemia, and the graft-vs-leukemia (GVL) effect can eradicate residual leukemia after allo-SCT. Ph( + ) leukemia cells frequently express death-inducing receptors (DR4 and DR5) for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is one of the cytotoxic ligands expressed on cytotoxic T cells and natural killer cells mediating the GVL effect. Here we demonstrate that imatinib specifically downregulated DR4 and DR5 expression in cell lines and clinical samples of Ph(+ ) leukemia. Second-generation tyrosine kinase inhibitors (dasatinib and nilotinib) and short hairpin RNA against bcr-abl also downregulated DR4 and DR5 expression in Ph( + ) leukemia cells, and transfection of bcr-abl into a Ph( —) leukemia cell line induced DR4 and DR5 expression, which was abrogated by imatinib treatment. Accordingly, Ph( + ) leukemia cells that had been pretreated with imatinib showed resistance to the pro-apoptotic activity of recombinant human soluble TRAIL. These observations demonstrate that BCR-ABL is critically involved in the leukemia-specific expression of DR4 and DR5 and in the susceptibility of Ph( + ) leukemia to TRAIL-mediated anti-leukemic activity, providing new insight into the mechanisms of the tumor-specific cytotoxic activities of TRAIL.