Plants can provide food, fuel, and building materials and also serve as an indispensable source of other specialty products such as flavors, perfumes, insecticides, and pharmaceuticals. Since Genetically Modified (GM) plants reached the markets during the mid-1990s, the world area of biotech crops has increased for thirteen consecutive years at an average growth rate of 12% in both developed and developing countries. The use of plants for medicinal purposes dates back thousands of years but genetic engineering of plants to produce desired biopharmaceuticals is much more recent. As the demand for biopharmaceuticals is expected to increase, it would be wise to ensure that they will be available in significantly larger amounts, on a cost-effective basis. Currently, the cost of biopharmaceuticals limits their availability. Plant-derived biopharmaceuticals are cheap to produce and store, easy to scale up for mass production, and safer than those derived from animals.