Establishment of a Strategy for Preventing Graft-versus-host Disease After Allogeneic Hematopoietic Cell Transplantation by Exploring Immune Mechanisms of Regulatory and Effector T Cells

"Sampling~1. patient~ 1. Peripheral blood samples in a volume of 25 cc will be collected before HCT and 2 weeks after HCT, and peripheral blood samples in a volume of 20 cc will be collected 4 weeks, 3 months, 6 months, and 12 months after HCT.~ 2. If GVHD occurs, additional blood sample (20 cc) will be collected.~ 3. In case of organ-specific GVHD including skin, gut, liver, muscle, etc., tissue samples from biopsy will be obtained for further analysis.~2. donor a. Peripheral blood samples in a volume of 20 cc will be collected before HCT"