Human Leukocyte Antigen (HLA) Mismatched Related Allogeneic Hematopoietic Stem Cell Transplantation

Inclusion Criteria: * Adult patients (18-60 years old) with hematological malignancies and indications for hematopoietic stem cell transplantation with no available related human leukocyte antigen (HLA) identical sibling donors; * No available donor with HLA high-resolution typing ≥ 9/10 or those who have difficulty finding donors due to urgent medical conditions; * No suitable HLA matching haploidentical donor available; * There is a suitable donor with mismatched HLA typing; * The subjects or their legal representatives shall sign an informed consent form before the start of the clinical study. Exclusion Criteria: * Patients with severe liver and kidney function (alanine aminotransferase\>2.5 times the upper limit of normal, blood creatinine\>1.5 times the upper limit of normal) and cardiopulmonary dysfunction (New York Heart Association (NYHA) III/IV heart function, ejection fraction\<50%, severe obstructive or restrictive ventilation dysfunction); * Merge active infections; * Eastern Cooperative Oncology Group (ECOG) score ≥ 2 points; * Secondary tumors with merged activity; * Severe central nervous system or mental illness leading to the inability to autonomously choose to enter or exit clinical trials; * Combine other allo HSCT contraindications.