What is the immune response and it's role when dealing with...

Blood transfusions
Rh incompatibility
Tissue transplants

First of all; blood transfusions- NOT GOOD. DNA is it's own for every individual. The DNA being put into another is like placing the life of someone else into another person's body. The immune system has to be weakened in order to accept the new DNA from the blood transfusion; thus making the immune system weak against sicknesses; which is the cause of AIDS.