21.   Another group would ban the cloning of embryos used to produce a human child, but would allow embryos to be created to grow tissue for medical purposes.

22.   High-protein, high-calorie diets have become part of treating a burn victim, who needs the nutrients to fight infection and grow new tissue.

23.   In some experiments, the cells differentiated into other types of cells, supporting the theory that heart, brain and other tissue could be grown from such cells.

24.   Researchers have found evidence that stem cells circulating in the bloodstream can grow new tissue in the liver, gut and skin.