How to Make a Chimera

The second way to make a chimera is to start at the embryonic level and introduce one animal cells into the embryo of another. The next step is essentially to inject rat stem cells into pigs now they did this but that failed because those animals have different gestation time so rats and mice are kind of closer together. Any organs that are grown would probably be rejected by humans because they have too much pig tissue in them. This could take years before they get to any kind of point where they're growing functional human organs.