Hematopoietic stem cell transplantation is the fundamental cure for many hematological diseases such as leukemia and lymphoma. However, the traditional “marrow-clearing” transplantation, which uses high-dose radiotherapy/chemotherapy as pretreatment protocol, makes the transplantation process very risky, such as: prolonged and severe hematopoietic suppression can cause cerebral hemorrhage, pulmonary hemorrhage, and bacterial/fungal sepsis, which often leads to early death; high-dose radiotherapy ( 12Gy) is not only prone to serious complications such as radiation pneumonia, hepatic vein occlusion syndrome, and cataracts, but can also affect the reproductive function of patients, causing infertility in young patients after transplantation. In addition, the incidence and severity of graft-versus-host disease are high; patients are slow to rebuild their immune function after transplantation and are prone to recurrent respiratory infections, skin herpes zoster, etc.; all of these seriously affect the quality of patients’ survival after transplantation. Moreover, patients who are older than 45 years old, frail and combined with other organ dysfunction are excluded from conventional transplantation treatment, but clinically a significant proportion of patients are older than 45 years old at the time of onset, mostly in their 50s, 60s and even older. How can more patients, including older patients, be cured of their disease by HSCT while avoiding or reducing the risks associated with transplantation and improving their quality of life after transplantation? As mentioned above, the many complications of traditional HSCT are mainly caused by high-dose radiotherapy/chemotherapy, i.e. “bone marrow clearance” pretreatment; in 1998, after extensive basic and clinical research, American and Israeli scholars successively proposed the concept and method of “non-cleared marrow HSCT In 1998, after a lot of basic and clinical research, American and Israeli scholars successively proposed the concept and method of “non-clear marrow HSCT”, i.e., by reducing the intensity of preconditioning and enhancing the immunomodulatory treatment before and after transplantation, a new “win-win” transplantation model was obtained. Non-cleared marrow HSCT rejects the high-dose radiotherapy/chemotherapy pretreatment used in traditional transplantation, and mainly uses low toxicity and low side effects drugs, such as fludarabine, cyclophosphamide, cytarabine, anti-lymphocyte globulin, etc., or combines with low-dose radiotherapy (2 Gy) to form a pretreatment regimen, which is not only well tolerated by patients, but also has mild pretreatment-related complications, manifesting only mild oral mucositis, nausea, stomach discomfort If a non-clearance pretreatment regimen without radiotherapy is used, complications such as radiation pneumonia, cataract and reproductive dysfunction can be completely avoided. The clinical results of nearly 10,000 cases of non-clear marrow transplantation at home and abroad show that non-clear marrow transplantation can not only completely cure acute and chronic leukemia, lymphoma, as well as heavy aplastic anemia, multiple myeloma, myelodysplastic syndrome, myelofibrosis and other diseases, achieving the same or even higher cure rates as clear marrow transplantation, but also has been successfully used in recent years for the treatment of thalassemia, sickle cell anemia and other In recent years, it has been successfully used for the treatment of hereditary blood diseases such as thalassemia and sickle cell anemia. Compared with clear marrow transplantation, hematopoietic reconstruction after non-clear marrow transplantation is rapid, more than 10 days or even 20 days earlier than clear marrow transplantation, which greatly shortens the period of myelosuppression and significantly reduces the early mortality rate, making hematopoietic stem cell transplantation safer and less risky; in addition, because the impact on the function of important organs of the body is reduced, many older, frail patients with combined damage to other organs can The maximum age of patients who have undergone non-cleared marrow transplantation so far has been reported to be 75 years abroad and 72 years in China; for young and infertile patients, their reproductive function is not affected after transplantation. More importantly, the incidence and severity of post-transplant graft-versus-host disease is significantly reduced due to the enhanced immunomodulatory treatment before and after transplantation, and more patients do not need to take long-term immunosuppressive drugs after transplantation, which accelerates immune reconstitution and improves the quality of life. In addition, non-cleared marrow transplant patients have significantly shorter hospital days and spend around 150,000 RMB for treatment, compared to 300,000 RMB or more for clear marrow transplant.