Figure 2. Regenerative medicine application of cells from the hair follicle.

Epithelial stem cells located in the bulge can give rise to the different epithelial lineages of the hair follicle. In response to wounding in the skin, bulge stem cells contribute to re-epithelialization of the epidermis. Comparatively, hair follicle dermal papilla and connective tissue sheath (dermal sheath) cells can differentiate into many cell types including osteoblasts and adipocytes. In a clinical trial for tendinosis, sheath cells are believed to differentiate into tenocyte-like cells.