Indolent lymphomas, including follicular lymphoma (FL), marginal zone lymphoma, lymphoplasmacytic lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, are characterized by a prolonged waxing and waning of the disease course and relatively long survival in most patients compared with their aggressive lymphoma counterparts.Twenty-three patients with r/r transformed lymphoma treated in the authors' center between Nov. 2017 and Nov. 2020 were enrolled in this study.The sum of the products of the longest perpendicular diameters was used to evaluate tumor burden.The sum of the products of the longest perpendicular diameters of each patient was calculated by multiplying the two longest perpendicular diameters of each target lesion under the guidance of a Computed tomog. imaging specialist.The best response was complete remission (CR) in 11 patients followed by partial remission (PR) in seven patients and progressive disease in four patients.By the study cutoff, eight patients who achieved CR maintained durable remission and the other three patients relapsed at 3 mo, 12 mo and 24 mo, with the patient who relapsed at 3 mo after CAR T-cell therapy alone dying of disease progression and the other two patients achieving stable disease with salvage therapy.With the exception of the aforementioned patient who died early, CAR T cells expanded well soon after infusion in all patients.After the first infusion, median peaks of CAR19 and CAR22 T cells in the blood appeared at 11.33 days (range, 218) and 10.04 days (range, 222), resp. .