This is a prospective observational study. The investigators plan to utilize this model as a tool for early classification and interrogate ANS function of transplant recipients.

Inclusion Criteria:

1. Patients must be > 16 years of age;
2. Patients receiving HLA-haploidentical transplants;
3. Patients have to sign an informed consent form before the start of the research procedure.

Exclusion Criteria:

1. Tandem transplantation or multiple transplantations;
2. Mental or other medical conditions that make the patients unable to comply with the research treatment and monitoring requirements;
3. Patients who are ineligible for the study due to other factors, or will bear great risk if participating in the study.

Adult patients receiving HLA-haploidentical transplants at the Institute of Hematology, Chinese Academy of Medical Sciences (IHCAMS)