So auto means we're dealing with that same individual and aloe means we're dealing with two different individuals. Now, as you might expect, the process of grafting and organ transplantation is actually a very, very complicated process. And that's because it deals with a great amount of precision, a great amount of analyzation and a great amount of preparation. Now, the primary reason, the primary thing that creates these complications is actually the immune system of that host individual that is accepting that graft or that organ. So let's discuss some of the major issues involved with transferring grafts as well as organs from one individual to a different individual. So let's examine graft rejection, let's discuss graft versus host disease and also infections.