CD19 and diffuse large B-cell lymphoma: In recent years, cellular immunotherapy has achieved important breakthroughs, especially CD19-chimeric antigen receptor T-cells (CAR-T-CD19) for the treatment of relapsed/refractory acute B lymphoblastic leukemia with up to 70%-90% complete remission rates, but in B-cell lymphomas such as DLBCL, CAR-T treatment did not achieve similar satisfactory results, with only about 50% of the response rate [4].