• Age 18-75 (inclusive).

• Patients with histologically confirmed CD19-positive B-cell NHL, including the following types defined by the World Health Organization (WHO) 2016:

‣ Diffuse large B-cell lymphoma not otherwise specified (DLBCL-NOS), including activated B-cell type (ABC) / germinal center B-cell Type (GCB);

⁃ Primary mediastinal (thymic) large B-cell lymphoma (PMBCL);

⁃ Transformed follicular lymphoma (TFL);

⁃ High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (HGBCL);

⁃ Follicular lymphoma (FL);

⁃ Mantle cell lymphoma (MCL) \[pathologically confirmed, with documentation of monoclonal B cells that have a chromosome translocation t(11;14)(q13;q32) and/or overexpress cyclin D1\];

⁃ Marginal zone lymphoma (MZL), including nodal or splenic marginal zone B-cell lymphoma and mucosa-associated lymphoid tissue (MALT) lymphoma.

• Relapse after treatment with ≥2 lines systemic therapy for all the above disease types, or refractory disease for aggressive types (DLBCL-NOS, PMBCL, TFL and HGBCL). Relapse disease is defined as disease progression after last regimen. Refractory disease is defined as no CR to first-line therapy:

‣ Evaluation of PD (never reached response or SD) after standard first-line treatment, or

⁃ SD as best response after at least 4 cycles of first-line therapy (eg, 4 cycles of R-CHOP), or

⁃ PR as best response after at least 6 cycles and biopsy-proven residual disease or disease progression ≤ 6 months of therapy, or

⁃ Refractory post-autologous stem cell transplant (ASCT): i. Disease progression or relapsed less than or equal to 12 months of ASCT (must have biopsy proven recurrence in relapsed individuals); ii. If salvage therapy is given post-ASCT, the individual must have had no response to or relapsed after the last line of therapy.

• Individuals must have received adequate prior therapy:

• For MCL, prior therapy must have included:

⁃ Anthracycline or bendamustine-containing chemotherapy and

⁃ Anti-CD20 monoclonal antibody (unless investigator determines that tumor is CD20-negative) and

⁃ Bruton tyrosine kinase inhibitor (BTKi)

• For other types, prior therapy must have included:

⁃ Anti-CD20 monoclonal antibody (unless investigator determines that tumor is CD20-negative) and

⁃ Anthracycline containing chemotherapy regimen.

• For individual with TFL must have relapse or refractory disease after transformation to DLBCL.

• The estimated survival time is over 3 months.

• The Eastern Cooperative Oncology Group (ECOG) score is 0-2.

• According to Lugano response criteria 2014, there should be at least one evaluable tumor focus. Evaluable tumor focus was defined as that with the longest diameter of intranodal focus \> 1.5cm, the longest diameter of extranodal focus \> 1.0cm assessed by computed tomography (CT) or magnetic resonance imaging (MRI).

• Subjects must be willing to undergo either excised or large-needle lymph node or tissue biopsy, or provide formalin-fixed paraffin-embedded (FFPE) tumor tissue block or freshly cut unstained slides.

• Functions of important organs meet the following requirements:

‣ Echocardiography showed left ventricular ejection fraction ≥50%;

⁃ Serum creatinine ≤1.5 × upper limit of normal range (ULN) or endogenous creatinine clearance ≥45mL/min (cockcroft-gault formula);

⁃ Total bilirubin ≤1.5× ULN;

⁃ Pulmonary function: ≤CTCAE grade 1 dyspnea and oxygen saturation of blood (SaO2) ≥91% in indoor air environment.

⁃ Blood routine: hemoglobin (Hgb) ≥ 80g/L, neutrophil count (ANC) ≥ 1 × 10 \^ 9/L, platelet count (PLT) ≥ 75 × 10 \^ 9/L. Excluding when there is bone marrow infiltration. It is not allowed to obtain normal values through growth factor intervention.

⁃ Pregnancy tests for women of childbearing age shall be negative; Both men and women agreed to use effective contraception during treatment and during the subsequent 1 year.

⁃ Toxicity from previous antitumor therapy ≤ grade 1 (according to CTCAE version 5.0) or to an acceptable level of inclusion/exclusion criteria (other toxicities such as alopecia and vitiligo considered by the investigator to pose no safety risk to the subject).

⁃ No obvious hereditary diseases.

⁃ Able to understand the requirements and matters of the trial, and willing to participate in clinical research as required.

⁃ Informed consent must be signed.