A transgenic animal is one that is genetically modified to carry genes from another species. Transgenic species can be raised to carry potentially useful genes from a variety of species. While the topics of genetic engineering and cloning are controversial, the reality is that these technologies offer tremendous benefits to society - from offering a framework for developing and screening medical therapies, to enhancing the safety and nutrition of the food we eat. One potential application of research into transgenic animal technology is the creation of domestic animals genetically designed to express a certain human disease and therefore serve as models for the study and treatment of human illnesses. Although many mouse models of human diseases are available today, such models in large domestic animals physiologically more similar to humans are sparse and critically needed. Further research in this field will undoubtedly uncover many more direct and indirect benefits of this (...)