But obviously we can't transplant things like the heart because we only have a single heart. Another good case scenario is if we have a twin. If we actually have an identical twin this creates very little complications because those two twins will have very similar, if not identical MHC major histor compatibility cells, antigen complexes. And so when we transplant an organ or tissue from one twin from one of the twins to different twins this will create very little complication and the immune system will accept that organ. Now of course these instances are actually very rare because not always do we have a twin and not always can we actually transplant an organ because we only have one of each organ not including things like our lungs or our kidneys. Now, two very common methods, much more common methods than what we just discussed are tissue typing and immunosuppression.