Embryonic stem cells can become any other kind of cell, giving them amazing potential for usage in medical care. In theory, that flexibility means stem cells could be used to replace defective or dying cells, making them a source of potential new cures and therapies for any number of chronic diseases or injuries. Stem cells could be this generation’s polio vaccine, with the potential of helping millions of Americans suffering from injuries and diseases such as Type 1 diabetes, breast cancer, sickle cell disease, Parkinson’s disease, among others.