Bone marrow transplantation is actually not exactly the same as organ transplantation. What is routinely referred to as bone marrow transplantation is actually the collection of the donor’s bone marrow, or donor’s hematopoietic stem cells. Organ transplantation, on the other hand, is mainly the collection of substantial organs of the donor, such as lungs, heart, and liver, and the collection is not exactly the same as bone marrow transplantation. So technically, the general direction of bone marrow transplantation can also be called organ transplantation, but it is very different from substantive organ transplantation. This is because when an organ transplant enters the body, it is primarily host rejection of the transplanted organ, whereas bone marrow transplantation is the opposite and is primarily graft-versus-host. However, the drugs used to mitigate the effects of graft rejection are partially the same, and both are treated with immunosuppressive drugs. Therefore, bone marrow transplantation and organ transplantation cannot be fully equated, and bone marrow transplantation may be relatively more severe than organ transplantation. The treatment used prior to transplantation is not exactly the same as organ transplantation, and bone marrow transplantation is more dangerous and risky than organ transplantation. Therefore, bone marrow transplantation and organ transplantation are not exactly the same treatment and do not treat the same diseases, so they cannot be equated with each other.