Prospective multicenter observational study of patients with relapsed or refractory diffuse large B-cell lymphoma starting second or third-line therapy and not receiving autologous stem cell transplant. (Real-mind) Purpose To understand treatment patterns of patients with relapsed or refractory large B-cell lymphoma starting second or third- line therapy Criteria Criteria: 1. At least 18 years old. 2. Confirmed diagnosis of relapsed or refractory large B-cell lymphoma after at least one prior systemic therapy and prior to second or third- line therapy. You cannot: 1. Be currently participating in an interventional clinical study. 2. Be receiving or planning to receive autologous stem cell transplant Details 1. Detailed history given at initial visit. 2. At each routine visit with the MD conducting the study data about therapy, treatment regimens, and adverse events will be collected. 3. No treatment provided. Data collection only. Interested in more information on clinical research? Contact WK Health System Clinical Research Department 318-212-8130 or ckay@wkhs.com Interested in more information? Contact Us: Joyce Feagin, M.D., Principal Investigator Hematology Oncology Associates (318) 212-8620 IRB: Western IRB Number: Trial Type: Device Sponsor: MorphoSys AG