Researchers and using stem cells as tools for disease study, drug screening, clinical trial strategy, and personalized medicine. The induced Pluripotent Stem cell (iPS) is giving us a chance to rethink the way we are developing new drugs. These iPS cells are usually created from somatic cells (such as skin), and not embryos or adult stem cells. In creating iPS from patients’ diseased cells, scientists can study the disease in vitro, looking for disease phenotypes, applying microenvironmental stress, and testing new drugs. Compared to animal model testing (e.g. mice), this represents a significant breakthrough, that can be used to validate clinical development strategy and test efficacy in specific groups of patients. iPS is bringing a revolution in drug discovery methodology which is being used to bridge genetics, cell biology, and physiology.