Raising a goat is far easier than standard methods of creating protein-based medicines, such as growing batches of altered cells or pulling proteins from donated human blood. It's also cost-effective. William Heiden, the CEO of GTC Biotherapeutics, the makers of ATryn, says that running a farm instead of building a dedicated production line saves his company hundreds of millions of dollars. And scaling up production is as easy as letting the animals mate. Some scientists warn that transgenic animals could introduce modified DNA into other herds, but these livestock could also drastically cut the prices of lifesaving drugs. Here, a look into a "pharmer's" medicine cabinet.