GT719 Injection for the Treatment of Recurrent/Refractory CD19 Positive Adult B-cell Malignancies

Inclusion Criteria: 1. Voluntarily enrolled in the study, signed an informed consent form, and willing and able to comply with the study protocol. \- 2. Eastern Collaborative Oncology Group (ECOG) physical fitness status score of 0 or 1. \- 3. CD19 positivity confirmed by flow cytometry and/or histopathology. Exclusion Criteria: 1. Primary immunodeficiency. \- 2. History of symptomatic deep vein thrombosis or pulmonary embolism within 6 months prior to enrollment, requiring systemic anticoagulant therapy. \- 3. Any medical condition that may interfere with the evaluation of the safety or effectiveness of research and treatment;