A stem cell is a little bit like a foundation. You can build anything you want on a foundation - a house, garage, store, restaurant, or so forth - but no matter what you want to build, it has to have a foundation under it. Researchers at stem cell companies know that stem cells can be used to repair all different kinds of damaged cells and tissues in the body, because the stem cell is a basic cell that is the foundation for differentiation into a specialized cell. However, they are only just beginning to discover how medical science can use healthy stem cells to alleviate and even cure all sorts of diseases.