The substitution of bortezomib for vincristine in R-CHOP resulted in higher rates of complete response and nearly a doubling in progression-free survival among patients with advanced mantle-cell lymphoma not eligible for stem-cell transplantation. Mantle-cell lymphoma is an incurable, aggressive hematologic cancer with a poor prognosis (median survival, 4 to 5 years). 1 , 2 It comprises 5 to 6% of all non-Hodgkin's lymphomas, including approximately 5000 cases per year in the United States. 3 For previously untreated patients who are either ineligible or not considered for intensive chemotherapy and stem-cell transplantation, R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) is a standard of care 4 – 6 and produces complete response rates of up to 48%. However, progression-free survival is limited (median, 16.6 months). 7 The proteasome inhibitor bortezomib was initially approved for the treatment of relapsed mantle-cell lymphoma in . . .