Figure 1. Organization of adult mouse epidermis.

1. The differentiated lineages of the interfollicular epidermis (IFE), sebaceous gland (SG) and hair follicle (HF) are shown. ORS, outer root sheath; IRS, inner root sheath.
2. In response to appropriate stimuli, stem cells (SC) in any region of the epidermis can give rise to any of the epidermal differentiated lineages. SCs are therefore represented as being interconvertible. Based on Owens and Watt (2003).