Bone marrow grafts are obtained from bone marrow sources, from hematopoietic stem cell sources, and from umbilical cord blood sources. Bone marrow in bone marrow transplants is generally collected through the posterior superior iliac spine site. The bone marrow required is usually red marrow, which has the hematopoietic component. In adulthood, the red marrow is often located in the flat bone, and the long bones are basically yellow marrow, so it does not have a hematopoietic component. Only in the flat bones and at the ends of the femur does the red bone marrow have a normal hematopoietic component. Therefore, in order to obtain red marrow, the flat bones are often taken, and the largest flat bone in the human body is the pelvis. The pelvis is divided into the anterior superior iliac spine and the posterior superior iliac spine. Since the anterior superior iliac spine is thicker, it is not particularly convenient to collect, so the posterior superior iliac spine is usually used, so the bone marrow is collected from the left side of the patient or the right side of the patient, and the red bone marrow is collected from the posterior superior iliac spine at the same time. However, most of them are currently collected from the donor’s peripheral blood stem cells, not bone marrow.