Traditionally, doctors treated severe burns by transplanting sections of skin from undamaged areas of the body onto the burned areas, but if doctors could not find enough unharmed skin to cover the burned areas, the patient could die. Now, scientists can grow vast sheets of new skin by culturing the stem cells from small pieces of a healthy skin. This practice, which is a type of tissue engineering, has become routine for treating burn victims. Recently, scientists have identified other types of stem cells in hair follicles and deeper layers of the skin. The inclusion of these new stem cells into enginered skin should help create more natural-looking skin transplants in the future.