These are example of why I made my statement.
Pigs are better suited to genetic cartography than cattle or sheep and their genome is recognisably similar to ours in size and organisation.
...
The project will benefit from similar work on the human genome, simply because the two maps will cover the same basic mammalian terrain. 'There is a lot of homology with the human genome,' says Haley. It is almost as if the pig's chromosomes are made by cutting human chromosomes into pieces and reuniting the pieces in a different order. Genes that occupy adjacent slots in the human genome are likely to do so in the pig.
http://www.newscientist.com/article/mg12717275.300-genetic-markers-put-pigs-on-the-map-.htmlThe Mayo Clinic research team has long been interested -- and is a world leader -- in xenotransplantation (ZEE-no-transplantation). This is an experimental field within transplant biology in which specially bred and raised pigs might eventually become donors for humans to meet the drastic shortage of suitable donor organs. Worldwide, thousands of people suffer failure of such organs as the liver, kidney, heart, lung and pancreas and require transplants -- but face death due to shortage of suitable donor organs. Xenotransplantation is just one experimental avenue being explored as a way to meet this shortage.
One central concern of investigators is the potential for zoonotic transmission of disease when an animal organ is surgically implanted into a human. One virus of concern is the porcine endogenous retrovirus, which is present in all pigs. The current research provided two important discoveries: the virus can pass to human cells in the body and it can be infectious. But whether it can actually cause disease in humans is not yet known.
http://www.eurekalert.org/pub_releases/2004-01/mc-mro010804.phpBiological valves are valves of animals, like pigs, which undergo several chemical procedures in order to make them suitable for implantation in the human heart. The porcine (or pig) heart is most similar to the human heart, and therefore represents the best anatomical fit for replacement.
http://en.wikipedia.org/wiki/Artificial_heart_valve