Bortezomib, a first-in-class proteasome inhibitor, induces apoptosis and growth arrest and reverses chemoresistance in myeloma cells and has demonstrated no irreversible adverse effect on haematopoietic stem cells. Bortezomib has shown in vitro and in vivo activity against a variety of malignancies, including myeloma, chronic lymphocytic leukemia, prostate cancer, pancreatic cancer, and colon cancer. The drug is rapidly cleared from the vascular compartment. Bortezomib showed promising activity in relapsed mantle-cell lymphoma and encouraging results in other B-cell lymphomas.