Adult stem cells are everywhere in the body - the difficulty lies in identifying and isolating them for therapeutic use. The promising nature of first generation stem cell transplant therapies means that new sources of adult stem cells can only be a good thing. In this short Washington Post article, we hear of new progress: "Japanese researchers have discovered stem cells in human heart tissue ... [the researchers] were able to culture stem cells from the samples that developed into different types of cells, including heart muscle cells, blood cells and neurons, the report said. Injections of the cells into a mouse that had suffered an embolism helped the animal regenerate damaged heart muscle and blood vessels. Similar tests are planned on dogs and pigs before conducting clinical tests on humans as early as next spring."