 This research study is for patients who have relapsed or refractory mantle cell lymphoma following treatment such as radiotherapy, immunotherapy, chemotherapy, or radioimmunotherapy. Currently, there is no clearly recommended standard treatment in this population. Chemotherapy agents such as gemcitabine, cytarabine, chlorambucil, fludarabine, or the immunotherapeutic agent, rituximab, may be proposed. Thus, the aim is to search for new treatments that may improve the prognosis of patients with relapsed mantle cell lymphoma. 