Development and homeostasis of the skin epidermis.

The skin epidermis is a stratified epithelium that forms a barrier that protects animals from dehydration, mechanical stress, and infections. The epidermis encompasses different appendages, such as the hair follicle (HF), the sebaceous gland (SG), the sweat gland, and the touch dome, that are essential for thermoregulation, sensing the environment, and influencing social behavior. The epidermis undergoes a constant turnover and distinct stem cells (SCs) are responsible for the homeostasis of the different epidermal compartments. Deregulation of the signaling pathways controlling the balance between renewal and differentiation often leads to cancer formation.