As well as "Dolly" the sheep, five piglets were cloned with organs compatible for humans. With this technology, if someone needs a specific organ, but a hospital does not have the organ on-hand from another human being, they could take the specified organ from an animal (such as a pig) to use instead. This is where pharming comes in: the process of genetically modifying plants and animals so that they produce substances that may be used as pharmaceuticals.

My concern with this, however, is that taking potentially an important organ for an animal could be considered inhumane and go against animal abuse laws. This was done in back in 2000, so I am not quite sure how far this research has gone since then.