Like other adult stem cells, those that reside in the skin are important for tissue homeostasis during normal cell turnover and wound healing. Multipotent skin stem cells are thought to reside within the so-called 'bulge', a niche within the hair follicle. These epidermal stem cells are generally quiescent but can be stimulated to proliferate and differentiate into the specialized cells that compose a hair follicle. Multipotent epidermal stem cells within the bulge can also be activated to regenerate the epidermis during wound healing. Epidermal stem cells have been characterized in vitro for skin graft purposes and are known to express Integrin alpha 6/CD49f and the general stem cell marker, CD34. An additional, unipotent stem cell population located within the interfollicular epidermis is thought to regulate normal epithelial cell turnover.